Using Technology to Obtain Descriptive Statistics
Let’s go to the technology now and recall how to load a data set in order to describe and explore it.
For Questions 4 and 5, recall the sleep study in which you investigated whether college students’ chronotypes tend to be larks (morning people) or owls (night people) by examining graphical representations of the data. Let’s use the data set from that study again here.
Go to the Describing and Exploring Quantitative Variables tool at https://dcmathpathways.shinyapps.io/EDA_quantitative/.
Step 1) Select the Single Group tab.
Step 2) Locate the drop-down menu under Enter Data and select From Textbook.
Step 3) Locate the drop-down menu under Data Set and select Sleep Study: Average Sleep.
question 4
question 5
Measures of Variability
In statistics, we are particularly interested in understanding how data are distributed and where each observation is in reference to the mean. How spread out a set of observations are is called variability (also called spread or dispersion). In the remainder of this section, we will focus on three measures of spread: standard deviation, variance, and range.
Recall
We’ll be using statistical formulas and symbols to discuss measures of variability. Take a moment to recall the formula you learned to calculate the mean of a sample. What symbols do we use to represent sample mean, summation, and sample size?
Core skill:
Continue to the next page to take a deeper dive into the different measures of variability (spread), beginning with standard deviation.
