{"id":77,"date":"2016-04-21T22:43:45","date_gmt":"2016-04-21T22:43:45","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/introstats1xmaster\/?post_type=chapter&#038;p=77"},"modified":"2017-07-20T22:56:51","modified_gmt":"2017-07-20T22:56:51","slug":"box-plots","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/suny-suffolk-introstats1\/chapter\/box-plots\/","title":{"raw":"Box Plots","rendered":"Box Plots"},"content":{"raw":"<strong>Box plots<\/strong> (also called <strong>box-and-whisker plots<\/strong> or <strong>box-whisker plots<\/strong>) give a good graphical image of the concentration of the data. They also show how far the extreme values are from most of the data. A box plot is constructed from five values: the minimum value, the first quartile, the median, the third quartile, and the maximum value. We use these values to compare how close other data values are to them.\r\n\r\nTo construct a box plot, use a horizontal or vertical number line and a rectangular box. The smallest and largest data values label the endpoints of the axis. The first quartile marks one end of the box and the third quartile marks the other end of the box. Approximately\u00a0<strong>the middle 50 percent of the data fall inside the box<\/strong>. The \"whiskers\" extend from the ends of the box to the smallest and largest data values. The median or second quartile can be between the first and third quartiles, or it can be one, or the other, or both. The box plot gives a good, quick picture of the data.\r\n\r\n<hr \/>\r\n\r\n<h4>Note<\/h4>\r\nYou may encounter box-and-whisker plots that have dots marking outlier values. In those cases, the whiskers are not extending to the minimum and maximum values.\r\n\r\n<hr \/>\r\n\r\nConsider, again, this dataset.\r\n\r\n1 1 2 2 4 6 6.8 7.2 8 8.3 9 10 10 11.5\r\n\r\nThe first quartile is two, the median is seven, and the third quartile is nine. The smallest value is one, and the largest value is 11.5. The following image shows the constructed box plot.\r\n\r\n<hr \/>\r\n\r\n\r\n\r\n<hr \/>\r\n\r\n<img src=\"https:\/\/textimgs.s3.amazonaws.com\/DE\/stats\/v3hb-maak3y6i#fixme#fixme#fixme\" alt=\"Horizontal boxplot's first whisker extends from the smallest value, 1, to the first quartile, 2, the box begins at the first quartile and extends to the third quartile, 9, a vertical dashed line is drawn at the median, 7, and the second whisker extends from the third quartile to the largest value of 11.5.\" \/>\r\n\r\nThe two whiskers extend from the first quartile to the smallest value and from the third quartile to the largest value. The median is shown with a dashed line.\r\n\r\n<hr \/>\r\n\r\n<h4>Note<\/h4>\r\nIt is important to start a box plot with a\u00a0<strong>scaled number line<\/strong>. Otherwise the box plot may not be useful.\r\n<div class=\"textbox exercises\">\r\n<h3>Example<\/h3>\r\nThe following data are the heights of 40 students in a statistics class.\r\n\r\n59 60 61 62 62 63 63 64 64 64 65 65 65 65 65 65 65 65 65 66 66 67 67 68 68 69 70 70 70 70 70 71 71 72 72 73 74 74 75 77\r\n\r\nConstruct a box plot with the following properties; the calculator instructions for the minimum and maximum values as well as the quartiles follow the example.\r\n<ul>\r\n \t<li>Minimum value = 59<\/li>\r\n \t<li>Maximum value = 77<\/li>\r\n \t<li><em>Q<\/em>1: First quartile = 64.5<\/li>\r\n \t<li><em>Q<\/em>2: Second quartile or median= 66<\/li>\r\n \t<li><em>Q<\/em>3: Third quartile = 70<\/li>\r\n<\/ul>\r\n<img style=\"width: 716px; height: 121.97783933518px;\" src=\"https:\/\/textimgs.s3.amazonaws.com\/DE\/stats\/db82-wjak3y6i#fixme#fixme#fixme\" alt=\"Horizontal boxplot with first whisker extending from smallest value, 59, to Q1, 64.5, box beginning from Q1 to Q3, 70, median dashed line at Q2, 66, and second whisker extending from Q3 to largest value, 77.\" \/>\r\n<ol>\r\n \t<li>Each quarter has approximately 25% of the data.<\/li>\r\n \t<li>The spreads of the four quarters are 64.5 \u2013 59 = 5.5 (first quarter), 66 \u2013 64.5 = 1.5 (second quarter), 70 \u2013 66 = 4 (third quarter), and 77 \u2013 70 = 7 (fourth quarter). So, the second quarter has the smallest spread and the fourth quarter has the largest spread.<\/li>\r\n \t<li>Range = maximum value \u2013 the minimum value = 77 \u2013 59 = 18<\/li>\r\n \t<li>Interquartile Range: <em>IQR<\/em> = <em>Q<\/em>3 \u2013 <em>Q<\/em>1 = 70 \u2013 64.5 = 5.5.<\/li>\r\n \t<li>The interval 59\u201365 has more than 25% of the data so it has more data in it than the interval 66 through 70 which has 25% of the data.<\/li>\r\n \t<li>The middle 50% (middle half) of the data has a range of 5.5 inches.<\/li>\r\n<\/ol>\r\nSolution:\r\n\r\nTo find the minimum, maximum, and quartiles:\r\n\r\nEnter data into the list editor (Pres STAT 1:EDIT). If you need to clear the list, arrow up to the name L1, press CLEAR, and then arrow down.\r\n\r\nPut the data values into the list L1.\r\n\r\nPress STAT and arrow to CALC. Press 1:1-VarStats. Enter L1.\r\n\r\nPress ENTER.\r\n\r\nUse the down and up arrow keys to scroll.\r\n\r\nSmallest value = 59.\r\n\r\nLargest value = 77.\r\n\r\n<em>Q<\/em>1: First quartile = 64.5.\r\n\r\n<em>Q<\/em>2: Second quartile or median = 66.\r\n\r\n<em>Q<\/em>3: Third quartile = 70.\r\n\r\nTo construct the box plot:\r\n\r\nPress 4:Plotsoff. Press ENTER.\r\n\r\nArrow down and then use the right arrow key to go to the fifth picture, which is the box plot. Press ENTER.\r\n\r\nArrow down to Xlist: Press 2nd 1 for L1\r\n\r\nArrow down to Freq: Press ALPHA. Press 1.\r\n\r\nPress Zoom. Press 9: ZoomStat.\r\n\r\nPress TRACE, and use the arrow keys to examine the box plot.\r\n\r\n<\/div>\r\n<div class=\"textbox key-takeaways\">\r\n<h3>Try It<\/h3>\r\nThe following data are the number of pages in 40 books on a shelf. Construct a box plot using a graphing calculator, and state the interquartile range.\r\n\r\n136 140 178 190 205 215 217 218 232 234 240 255 270 275 290 301 303 315 317 318 326 333 343 349 360 369 377 388 391 392 398 400 402 405 408 422 429 450 475 512\r\n\r\n<img style=\"width: 722px; height: 92px;\" src=\"https:\/\/textimgs.s3.amazonaws.com\/DE\/stats\/k14d-4rak3y6i#fixme#fixme#fixme\" alt=\"\" \/><em>IQR<\/em> = 158\r\n\r\n<\/div>\r\n\r\n<hr \/>\r\n\r\nThis video explains what descriptive statistics are needed to create a box and whisker plot.\r\n\r\nhttps:\/\/www.youtube.com\/watch?v=GMb6HaLXmjY\r\n\r\nFor some sets of data, some of the largest value, smallest value, first quartile, median, and third quartile may be the same. For instance, you might have a data set in which the median and the third quartile are the same. In this case, the diagram would not have a dotted line inside the box displaying the median. The right side of the box would display both the third quartile and the median. For example, if the smallest value and the first quartile were both one, the median and the third quartile were both five, and the largest value was seven, the box plot would look like:\r\n\r\n<img src=\"https:\/\/textimgs.s3.amazonaws.com\/DE\/stats\/rz9u-swak3y6i#fixme#fixme#fixme\" alt=\"Horizontal boxplot box begins at the smallest value and Q1, 1, until the Q3 and median, 5, no median line is designated, and has its lone whisker extending from the Q3 to the largest value, 7.\" \/>\r\n\r\nIn this case, at least 25% of the values are equal to one. Twenty-five percent of the values are between one and five, inclusive. At least 25% of the values are equal to five. The top 25% of the values fall between five and seven, inclusive.\r\n<div class=\"textbox exercises\">\r\n<h3>Example<\/h3>\r\nTest scores for a college statistics class held during the day are:\r\n\r\n99 56 78 55.5 32 90 80 81 56 59 45 77 84.5 84 70 72 68 32 79 90\r\n\r\nTest scores for a college statistics class held during the evening are:\r\n\r\n98 78 68 83 81 89 88 76 65 45 98 90 80 84.5 85 79 78 98 90 79 81 25.5\r\n<ol>\r\n \t<li>Find the smallest and largest values, the median, and the first and third quartile for the day class.<\/li>\r\n \t<li>Find the smallest and largest values, the median, and the first and third quartile for the night class.<\/li>\r\n \t<li>For each data set, what percentage of the data is between the smallest value and the first quartile? the first quartile and the median? the median and the third quartile? the third quartile and the largest value? What percentage of the data is between the first quartile and the largest value?<\/li>\r\n \t<li>Create a box plot for each set of data. Use one number line for both box plots.<\/li>\r\n \t<li>Which box plot has the widest spread for the middle 50% of the data (the data between the first and third quartiles)? What does this mean for that set of data in comparison to the other set of data?<\/li>\r\n<\/ol>\r\nSolution:\r\n<ol>\r\n \t<li>\r\n<ul>\r\n \t<li>Min = 32<\/li>\r\n \t<li><em>Q<\/em>1 = 56<\/li>\r\n \t<li><em>M<\/em> = 74.5<\/li>\r\n \t<li><em>Q<\/em>3 = 82.5<\/li>\r\n \t<li>Max = 99<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li>\r\n<ul>\r\n \t<li>Min = 25.5<\/li>\r\n \t<li><em>Q<\/em>1 = 78<\/li>\r\n \t<li><em>M<\/em> = 81<\/li>\r\n \t<li><em>Q<\/em>3 = 89<\/li>\r\n \t<li>Max = 98<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li>Day class: There are six data values ranging from 32 to 56: 30%. There are six data values ranging from 56 to 74.5: 30%. There are five data values ranging from 74.5 to 82.5: 25%. There are five data values ranging from 82.5 to 99: 25%. There are 16 data values between the first quartile, 56, and the largest value, 99: 75%. Night class:<\/li>\r\n \t<li><img src=\"https:\/\/textimgs.s3.amazonaws.com\/DE\/stats\/356f-03bk3y6i#fixme#fixme#fixme\" alt=\"Two box plots over a number line from 0 to 100. The top plot shows a whisker from 32 to 56, a solid line at 56, a dashed line at 74.5, a solid line at 82.5, and a whisker from 82.5 to 99. The lower plot shows a whisker from 25.5 to 78, solid line at 78, dashed line at 81, solid line at 89, and a whisker from 89 to 98.\" \/><\/li>\r\n \t<li>The first data set has the wider spread for the middle 50% of the data. The <em>IQR<\/em> for the first data set is greater than the <em>IQR<\/em> for the second set. This means that there is more variability in the middle 50% of the first data set.<\/li>\r\n<\/ol>\r\n<\/div>\r\n<div class=\"textbox key-takeaways\">\r\n<h3>try it<\/h3>\r\nThe following data set shows the heights in inches for the boys in a class of 40 students.\r\n\r\n66; 66; 67; 67; 68; 68; 68; 68; 68; 69; 69; 69; 70; 71; 72; 72; 72; 73; 73; 74\r\n\r\nThe following data set shows the heights in inches for the girls in a class of 40 students.\r\n\r\n61; 61; 62; 62; 63; 63; 63; 65; 65; 65; 66; 66; 66; 67; 68; 68; 68; 69; 69; 69\r\n\r\nConstruct a box plot using a graphing calculator for each data set, and state which box plot has the wider spread for the middle 50% of the data.\r\n\r\n<img style=\"width: 697px; height: 221.070637119114px;\" src=\"https:\/\/textimgs.s3.amazonaws.com\/DE\/stats\/cywa-ldbk3y6i#fixme#fixme#fixme\" alt=\"\" \/><em>IQR<\/em> for the boys = 4\r\n\r\n<em>IQR<\/em> for the girls = 5\r\n\r\nThe box plot for the heights of the girls has the wider spread for the middle 50% of the data.\r\n\r\n<\/div>\r\n<div class=\"textbox exercises\">\r\n<h3>example<\/h3>\r\nGraph a box-and-whisker plot for the data values shown.\r\n\r\n10 10 10 15 35 75 90 95 100 175 420 490 515 515 790\r\n\r\nThe five numbers used to create a box-and-whisker plot are:\r\n<ul>\r\n \t<li>Min: 10<\/li>\r\n \t<li><em>Q<\/em>1: 15<\/li>\r\n \t<li>Med: 95<\/li>\r\n \t<li><em>Q<\/em>3: 490<\/li>\r\n \t<li>Max: 790<\/li>\r\n<\/ul>\r\nThe following graph shows the box-and-whisker plot.\r\n\r\n<img src=\"https:\/\/textimgs.s3.amazonaws.com\/DE\/stats\/h4d4-6jbk3y6i#fixme#fixme#fixme\" alt=\"\" \/>\r\n\r\n<\/div>\r\n<div class=\"textbox key-takeaways\">\r\n<h3>Try It<\/h3>\r\nFollow the steps you used to graph a box-and-whisker plot for the data values shown.\r\n\r\n0 5 5 15 30 30 45 50 50 60 75 110 140 240 330\r\n\r\nThe data are in order from least to greatest. There are 15 values, so the eighth number in order is the median: 50. There are seven data values written to the left of the median and 7 values to the right. The five values that are used to create the boxplot are:\r\n<ul>\r\n \t<li>Min: 0<\/li>\r\n \t<li><em>Q<\/em>1: 15<\/li>\r\n \t<li>Med: 50<\/li>\r\n \t<li><em>Q<\/em>3: 110<\/li>\r\n \t<li>Max: 330<\/li>\r\n<\/ul>\r\n<img src=\"https:\/\/textimgs.s3.amazonaws.com\/DE\/stats\/oso4-3pbk3y6i#fixme#fixme#fixme\" alt=\"\" \/>\r\n\r\n<\/div>\r\n&nbsp;\r\n\r\n<hr \/>\r\n\r\n<h2>References<\/h2>\r\nData from <em>West Magazine<\/em>.\r\n<h2>Concept Review<\/h2>\r\nBox plots are a type of graph that can help visually organize data. To graph a box plot the following data points must be calculated: the minimum value, the first quartile, the median, the third quartile, and the maximum value. Once the box plot is graphed, you can display and compare distributions of data.\r\n<h2>Additional Resources<\/h2>\r\nUse the <a href=\"http:\/\/www.imathas.com\/stattools\/boxplot.html\" target=\"_blank\" rel=\"noopener\">online imathAS box plot tool <\/a>to create box and whisker plots.","rendered":"<p><strong>Box plots<\/strong> (also called <strong>box-and-whisker plots<\/strong> or <strong>box-whisker plots<\/strong>) give a good graphical image of the concentration of the data. They also show how far the extreme values are from most of the data. A box plot is constructed from five values: the minimum value, the first quartile, the median, the third quartile, and the maximum value. We use these values to compare how close other data values are to them.<\/p>\n<p>To construct a box plot, use a horizontal or vertical number line and a rectangular box. The smallest and largest data values label the endpoints of the axis. The first quartile marks one end of the box and the third quartile marks the other end of the box. Approximately\u00a0<strong>the middle 50 percent of the data fall inside the box<\/strong>. The &#8220;whiskers&#8221; extend from the ends of the box to the smallest and largest data values. The median or second quartile can be between the first and third quartiles, or it can be one, or the other, or both. The box plot gives a good, quick picture of the data.<\/p>\n<hr \/>\n<h4>Note<\/h4>\n<p>You may encounter box-and-whisker plots that have dots marking outlier values. In those cases, the whiskers are not extending to the minimum and maximum values.<\/p>\n<hr \/>\n<p>Consider, again, this dataset.<\/p>\n<p>1 1 2 2 4 6 6.8 7.2 8 8.3 9 10 10 11.5<\/p>\n<p>The first quartile is two, the median is seven, and the third quartile is nine. The smallest value is one, and the largest value is 11.5. The following image shows the constructed box plot.<\/p>\n<hr \/>\n<hr \/>\n<p><img decoding=\"async\" src=\"https:\/\/textimgs.s3.amazonaws.com\/DE\/stats\/v3hb-maak3y6i#fixme#fixme#fixme\" alt=\"Horizontal boxplot's first whisker extends from the smallest value, 1, to the first quartile, 2, the box begins at the first quartile and extends to the third quartile, 9, a vertical dashed line is drawn at the median, 7, and the second whisker extends from the third quartile to the largest value of 11.5.\" \/><\/p>\n<p>The two whiskers extend from the first quartile to the smallest value and from the third quartile to the largest value. The median is shown with a dashed line.<\/p>\n<hr \/>\n<h4>Note<\/h4>\n<p>It is important to start a box plot with a\u00a0<strong>scaled number line<\/strong>. Otherwise the box plot may not be useful.<\/p>\n<div class=\"textbox exercises\">\n<h3>Example<\/h3>\n<p>The following data are the heights of 40 students in a statistics class.<\/p>\n<p>59 60 61 62 62 63 63 64 64 64 65 65 65 65 65 65 65 65 65 66 66 67 67 68 68 69 70 70 70 70 70 71 71 72 72 73 74 74 75 77<\/p>\n<p>Construct a box plot with the following properties; the calculator instructions for the minimum and maximum values as well as the quartiles follow the example.<\/p>\n<ul>\n<li>Minimum value = 59<\/li>\n<li>Maximum value = 77<\/li>\n<li><em>Q<\/em>1: First quartile = 64.5<\/li>\n<li><em>Q<\/em>2: Second quartile or median= 66<\/li>\n<li><em>Q<\/em>3: Third quartile = 70<\/li>\n<\/ul>\n<p><img decoding=\"async\" style=\"width: 716px; height: 121.97783933518px;\" src=\"https:\/\/textimgs.s3.amazonaws.com\/DE\/stats\/db82-wjak3y6i#fixme#fixme#fixme\" alt=\"Horizontal boxplot with first whisker extending from smallest value, 59, to Q1, 64.5, box beginning from Q1 to Q3, 70, median dashed line at Q2, 66, and second whisker extending from Q3 to largest value, 77.\" \/><\/p>\n<ol>\n<li>Each quarter has approximately 25% of the data.<\/li>\n<li>The spreads of the four quarters are 64.5 \u2013 59 = 5.5 (first quarter), 66 \u2013 64.5 = 1.5 (second quarter), 70 \u2013 66 = 4 (third quarter), and 77 \u2013 70 = 7 (fourth quarter). So, the second quarter has the smallest spread and the fourth quarter has the largest spread.<\/li>\n<li>Range = maximum value \u2013 the minimum value = 77 \u2013 59 = 18<\/li>\n<li>Interquartile Range: <em>IQR<\/em> = <em>Q<\/em>3 \u2013 <em>Q<\/em>1 = 70 \u2013 64.5 = 5.5.<\/li>\n<li>The interval 59\u201365 has more than 25% of the data so it has more data in it than the interval 66 through 70 which has 25% of the data.<\/li>\n<li>The middle 50% (middle half) of the data has a range of 5.5 inches.<\/li>\n<\/ol>\n<p>Solution:<\/p>\n<p>To find the minimum, maximum, and quartiles:<\/p>\n<p>Enter data into the list editor (Pres STAT 1:EDIT). If you need to clear the list, arrow up to the name L1, press CLEAR, and then arrow down.<\/p>\n<p>Put the data values into the list L1.<\/p>\n<p>Press STAT and arrow to CALC. Press 1:1-VarStats. Enter L1.<\/p>\n<p>Press ENTER.<\/p>\n<p>Use the down and up arrow keys to scroll.<\/p>\n<p>Smallest value = 59.<\/p>\n<p>Largest value = 77.<\/p>\n<p><em>Q<\/em>1: First quartile = 64.5.<\/p>\n<p><em>Q<\/em>2: Second quartile or median = 66.<\/p>\n<p><em>Q<\/em>3: Third quartile = 70.<\/p>\n<p>To construct the box plot:<\/p>\n<p>Press 4:Plotsoff. Press ENTER.<\/p>\n<p>Arrow down and then use the right arrow key to go to the fifth picture, which is the box plot. Press ENTER.<\/p>\n<p>Arrow down to Xlist: Press 2nd 1 for L1<\/p>\n<p>Arrow down to Freq: Press ALPHA. Press 1.<\/p>\n<p>Press Zoom. Press 9: ZoomStat.<\/p>\n<p>Press TRACE, and use the arrow keys to examine the box plot.<\/p>\n<\/div>\n<div class=\"textbox key-takeaways\">\n<h3>Try It<\/h3>\n<p>The following data are the number of pages in 40 books on a shelf. Construct a box plot using a graphing calculator, and state the interquartile range.<\/p>\n<p>136 140 178 190 205 215 217 218 232 234 240 255 270 275 290 301 303 315 317 318 326 333 343 349 360 369 377 388 391 392 398 400 402 405 408 422 429 450 475 512<\/p>\n<p><img decoding=\"async\" style=\"width: 722px; height: 92px;\" src=\"https:\/\/textimgs.s3.amazonaws.com\/DE\/stats\/k14d-4rak3y6i#fixme#fixme#fixme\" alt=\"\" \/><em>IQR<\/em> = 158<\/p>\n<\/div>\n<hr \/>\n<p>This video explains what descriptive statistics are needed to create a box and whisker plot.<\/p>\n<p><iframe loading=\"lazy\" id=\"oembed-1\" title=\"Box and Whisker Plot\" width=\"500\" height=\"375\" src=\"https:\/\/www.youtube.com\/embed\/GMb6HaLXmjY?feature=oembed&#38;rel=0\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p>For some sets of data, some of the largest value, smallest value, first quartile, median, and third quartile may be the same. For instance, you might have a data set in which the median and the third quartile are the same. In this case, the diagram would not have a dotted line inside the box displaying the median. The right side of the box would display both the third quartile and the median. For example, if the smallest value and the first quartile were both one, the median and the third quartile were both five, and the largest value was seven, the box plot would look like:<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/textimgs.s3.amazonaws.com\/DE\/stats\/rz9u-swak3y6i#fixme#fixme#fixme\" alt=\"Horizontal boxplot box begins at the smallest value and Q1, 1, until the Q3 and median, 5, no median line is designated, and has its lone whisker extending from the Q3 to the largest value, 7.\" \/><\/p>\n<p>In this case, at least 25% of the values are equal to one. Twenty-five percent of the values are between one and five, inclusive. At least 25% of the values are equal to five. The top 25% of the values fall between five and seven, inclusive.<\/p>\n<div class=\"textbox exercises\">\n<h3>Example<\/h3>\n<p>Test scores for a college statistics class held during the day are:<\/p>\n<p>99 56 78 55.5 32 90 80 81 56 59 45 77 84.5 84 70 72 68 32 79 90<\/p>\n<p>Test scores for a college statistics class held during the evening are:<\/p>\n<p>98 78 68 83 81 89 88 76 65 45 98 90 80 84.5 85 79 78 98 90 79 81 25.5<\/p>\n<ol>\n<li>Find the smallest and largest values, the median, and the first and third quartile for the day class.<\/li>\n<li>Find the smallest and largest values, the median, and the first and third quartile for the night class.<\/li>\n<li>For each data set, what percentage of the data is between the smallest value and the first quartile? the first quartile and the median? the median and the third quartile? the third quartile and the largest value? What percentage of the data is between the first quartile and the largest value?<\/li>\n<li>Create a box plot for each set of data. Use one number line for both box plots.<\/li>\n<li>Which box plot has the widest spread for the middle 50% of the data (the data between the first and third quartiles)? What does this mean for that set of data in comparison to the other set of data?<\/li>\n<\/ol>\n<p>Solution:<\/p>\n<ol>\n<li>\n<ul>\n<li>Min = 32<\/li>\n<li><em>Q<\/em>1 = 56<\/li>\n<li><em>M<\/em> = 74.5<\/li>\n<li><em>Q<\/em>3 = 82.5<\/li>\n<li>Max = 99<\/li>\n<\/ul>\n<\/li>\n<li>\n<ul>\n<li>Min = 25.5<\/li>\n<li><em>Q<\/em>1 = 78<\/li>\n<li><em>M<\/em> = 81<\/li>\n<li><em>Q<\/em>3 = 89<\/li>\n<li>Max = 98<\/li>\n<\/ul>\n<\/li>\n<li>Day class: There are six data values ranging from 32 to 56: 30%. There are six data values ranging from 56 to 74.5: 30%. There are five data values ranging from 74.5 to 82.5: 25%. There are five data values ranging from 82.5 to 99: 25%. There are 16 data values between the first quartile, 56, and the largest value, 99: 75%. Night class:<\/li>\n<li><img decoding=\"async\" src=\"https:\/\/textimgs.s3.amazonaws.com\/DE\/stats\/356f-03bk3y6i#fixme#fixme#fixme\" alt=\"Two box plots over a number line from 0 to 100. The top plot shows a whisker from 32 to 56, a solid line at 56, a dashed line at 74.5, a solid line at 82.5, and a whisker from 82.5 to 99. The lower plot shows a whisker from 25.5 to 78, solid line at 78, dashed line at 81, solid line at 89, and a whisker from 89 to 98.\" \/><\/li>\n<li>The first data set has the wider spread for the middle 50% of the data. The <em>IQR<\/em> for the first data set is greater than the <em>IQR<\/em> for the second set. This means that there is more variability in the middle 50% of the first data set.<\/li>\n<\/ol>\n<\/div>\n<div class=\"textbox key-takeaways\">\n<h3>try it<\/h3>\n<p>The following data set shows the heights in inches for the boys in a class of 40 students.<\/p>\n<p>66; 66; 67; 67; 68; 68; 68; 68; 68; 69; 69; 69; 70; 71; 72; 72; 72; 73; 73; 74<\/p>\n<p>The following data set shows the heights in inches for the girls in a class of 40 students.<\/p>\n<p>61; 61; 62; 62; 63; 63; 63; 65; 65; 65; 66; 66; 66; 67; 68; 68; 68; 69; 69; 69<\/p>\n<p>Construct a box plot using a graphing calculator for each data set, and state which box plot has the wider spread for the middle 50% of the data.<\/p>\n<p><img decoding=\"async\" style=\"width: 697px; height: 221.070637119114px;\" src=\"https:\/\/textimgs.s3.amazonaws.com\/DE\/stats\/cywa-ldbk3y6i#fixme#fixme#fixme\" alt=\"\" \/><em>IQR<\/em> for the boys = 4<\/p>\n<p><em>IQR<\/em> for the girls = 5<\/p>\n<p>The box plot for the heights of the girls has the wider spread for the middle 50% of the data.<\/p>\n<\/div>\n<div class=\"textbox exercises\">\n<h3>example<\/h3>\n<p>Graph a box-and-whisker plot for the data values shown.<\/p>\n<p>10 10 10 15 35 75 90 95 100 175 420 490 515 515 790<\/p>\n<p>The five numbers used to create a box-and-whisker plot are:<\/p>\n<ul>\n<li>Min: 10<\/li>\n<li><em>Q<\/em>1: 15<\/li>\n<li>Med: 95<\/li>\n<li><em>Q<\/em>3: 490<\/li>\n<li>Max: 790<\/li>\n<\/ul>\n<p>The following graph shows the box-and-whisker plot.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/textimgs.s3.amazonaws.com\/DE\/stats\/h4d4-6jbk3y6i#fixme#fixme#fixme\" alt=\"\" \/><\/p>\n<\/div>\n<div class=\"textbox key-takeaways\">\n<h3>Try It<\/h3>\n<p>Follow the steps you used to graph a box-and-whisker plot for the data values shown.<\/p>\n<p>0 5 5 15 30 30 45 50 50 60 75 110 140 240 330<\/p>\n<p>The data are in order from least to greatest. There are 15 values, so the eighth number in order is the median: 50. There are seven data values written to the left of the median and 7 values to the right. The five values that are used to create the boxplot are:<\/p>\n<ul>\n<li>Min: 0<\/li>\n<li><em>Q<\/em>1: 15<\/li>\n<li>Med: 50<\/li>\n<li><em>Q<\/em>3: 110<\/li>\n<li>Max: 330<\/li>\n<\/ul>\n<p><img decoding=\"async\" src=\"https:\/\/textimgs.s3.amazonaws.com\/DE\/stats\/oso4-3pbk3y6i#fixme#fixme#fixme\" alt=\"\" \/><\/p>\n<\/div>\n<p>&nbsp;<\/p>\n<hr \/>\n<h2>References<\/h2>\n<p>Data from <em>West Magazine<\/em>.<\/p>\n<h2>Concept Review<\/h2>\n<p>Box plots are a type of graph that can help visually organize data. To graph a box plot the following data points must be calculated: the minimum value, the first quartile, the median, the third quartile, and the maximum value. Once the box plot is graphed, you can display and compare distributions of data.<\/p>\n<h2>Additional Resources<\/h2>\n<p>Use the <a href=\"http:\/\/www.imathas.com\/stattools\/boxplot.html\" target=\"_blank\" rel=\"noopener\">online imathAS box plot tool <\/a>to create box and whisker plots.<\/p>\n\n\t\t\t <section class=\"citations-section\" role=\"contentinfo\">\n\t\t\t <h3>Candela Citations<\/h3>\n\t\t\t\t\t <div>\n\t\t\t\t\t\t <div id=\"citation-list-77\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>OpenStax, Statistics, Box Plots. <strong>Provided by<\/strong>: OpenStax. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"http:\/\/cnx.org\/contents\/30189442-6998-4686-ac05-ed152b91b9de@17.34:13\/Introductory_Statistics\">http:\/\/cnx.org\/contents\/30189442-6998-4686-ac05-ed152b91b9de@17.34:13\/Introductory_Statistics<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em><\/li><li>Introductory Statistics . <strong>Authored by<\/strong>: Barbara Illowski, Susan Dean. <strong>Provided by<\/strong>: Open Stax. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"http:\/\/cnx.org\/contents\/30189442-6998-4686-ac05-ed152b91b9de@17.44\">http:\/\/cnx.org\/contents\/30189442-6998-4686-ac05-ed152b91b9de@17.44<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em>. <strong>License Terms<\/strong>: Download for free at http:\/\/cnx.org\/contents\/30189442-6998-4686-ac05-ed152b91b9de@17.44<\/li><\/ul><div class=\"license-attribution-dropdown-subheading\">All rights reserved content<\/div><ul class=\"citation-list\"><li>Box and Whisker Plot. <strong>Authored by<\/strong>: patrickJMT. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/www.youtube.com\/watch?v=GMb6HaLXmjY\">https:\/\/www.youtube.com\/watch?v=GMb6HaLXmjY<\/a>. <strong>License<\/strong>: <em>All Rights Reserved<\/em>. <strong>License Terms<\/strong>: Standard YouTube License<\/li><\/ul><\/div>\n\t\t\t\t\t\t <\/div>\n\t\t\t\t\t <\/div>\n\t\t\t <\/section>","protected":false},"author":21,"menu_order":5,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"OpenStax, Statistics, Box Plots\",\"author\":\"\",\"organization\":\"OpenStax\",\"url\":\"http:\/\/cnx.org\/contents\/30189442-6998-4686-ac05-ed152b91b9de@17.34:13\/Introductory_Statistics\",\"project\":\"\",\"license\":\"cc-by\",\"license_terms\":\"\"},{\"type\":\"copyrighted_video\",\"description\":\"Box and Whisker Plot\",\"author\":\"patrickJMT\",\"organization\":\"\",\"url\":\"https:\/\/www.youtube.com\/watch?v=GMb6HaLXmjY\",\"project\":\"\",\"license\":\"arr\",\"license_terms\":\"Standard YouTube 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