15D

Type of residence
Urban Suburban Rural Total
Number of books read None 133 144 81 358
1–4 146 149 53 348
5–9 76 74 33 183
10+ 194 216 76 486
Total 549 583 243 1,375
Urban
Number of books read None 133
1–4 146
5–9 76
10+ 194
Total 549
Urban
Relative frequency of books read as a percentage None 0.2423
1–4
5–9
10+
Total 1
< $30,000 $30,000–$74,999 $75,000 and up Total
Post-Grad Degree 18.507 56
Observed count proportion Income level
<$30,000 $30,000–$74,999 $75,000 and up Total
Education level Post-Grad Degree 2 8 46 56

0.04354588
College Degree 39 113 202 354

 
Some College 131 138 120 389

 
HS Grad 175 129 65 369

 
No HS Degree 78 32 8 118

 
Total 425

0.33048212

 420

 

 441

 

 1,286

1
Number of books read None 358
1–4 348
5–9 183
10+ 486
Total 1,375
Relative frequency of number of books read as a percentage None
1–4
5–9
10+
Total 100%
Type of residence
Urban Suburban Rural Total
Number of books read None 133 144 81 358
1–4 146 149 53 348
5–9 76 74 33 183
10+ 194 216 76 486
Total 549 583 243 1,375
Relative frequency of number of books read as a percentage None 0.26036364
1–4 0.25309091
5–9 0.13309091
10+ 0.35345455
Total 1
Observed Expected
Number of books read by urban dwellers None 133 142.940
1–4 146 138.947
5–9 76 73.067
10+ 194 194.046
Total 549 549
Count Income level
< $30,000 $30,000–$74,999 $75,000 and up Total
Education level Post-Grad Degree 2 8 46 56
College Degree 39 113 202 354
Some College 131 138 120 389
HS Grad 175 129 65 369
No HS Degree 78 32 8 118
Total 425 420 441 1,286
Type of residence
Urban Suburban Rural
Number of books read None 133 144 81
1–4 146 149 53
5–9 76 74 33
10+ 194 216 76
Age bracket
18–29 30–49 50–64 65+
Device used to go online Mostly Cell 179 231 100 42
Mostly Other 64 94 122 67
Equally/Depends 53 124 63 34
Non-Smartphone 13 38 78 136
Count Income level
<$30,000 $30,000–$74,999 $75,000 and up Total
Education level Post-Grad Degree 2 8 46 56
College Degree 39 113 202 354
Some College 131 138 120 389
HS Grad 175 129 65 369
No HS Degree 78 32 8 118
Total 425 420 441 1,286
< $30,000
Post-Grad Degree 18.507
College Degree
Some College
High School Degree
No High School Degree
Total 425
Skill or Concept: I can . . . Questions to check your understanding Rating
from 1 to 5
Understand the difference between the chi-square test of homogeneity and the chi-square test of independence. 1
Understand what it means for two variables to be independent. 3–6
Identify the null and alternative hypotheses for a chi-square test of independence. 2
Find expected counts for the cells of the contingency table in a chi-square test of independence. 3–6
conditional distribution
the counts or the relative frequencies of one variable restricted to only that value of a second variable.
marginal distribution
the distribution of one of the variables with no regard to the other variable whatsoever.
lurking variable
a third variable not included in the study that impacts the values of both of the variables being considered.
independent
knowing whether event B happens has no effect on how likely event A is to occur.