In: Math
Assignment #8: Chi-Square Test of Independence Directions:
Use the Crosstabs option in the Descriptives menu to answer the questions based on the following scenario. (Be sure to select Chi-square from the Statistics submenu and Observed, Expected, Row, and Column in the Cells submenu. Assume a level of significance of .05)
The school district recently adopted the use of e-textbooks, and the superintendent is interested in determining the level of satisfaction with e-textbooks among students and if there is a relationship between the level of satisfaction and student classification. The superintendent selected a sample of students from one high school and asked them how satisfied they were with the use of e-textbooks. The data that were collected are presented in the following table.
Student Classification (N = 126)
Satisfied Freshmen Sophomore Junior Senior
Yes 13 13 21 20
No 22 17 8 12
1. Of the students that were satisfied, what percent were Freshmen, Sophomore, Junior, and Senior? (Round your final answer to 1 decimal place).
2. State an appropriate null hypothesis for this analysis.
3. What is the value of the chi-square statistic?
4. What are the reported degrees of freedom?
5. What is the reported level of significance?
6. Based on the results of the chi-square test of independence, is there an association between e-textbook satisfaction and academic classification?
7. Present the results as they might appear in an article. This must include a table and narrative statement that reports and interprets the results of the analysis.
Note: The table must be created using your word processing program. Tables that are copied and pasted from SPSS are not acceptable.
Following table shows the row total and column total:
Satisfied | Freshmen | Sophomore | Junior | Senior | Total |
Yes | 13 | 13 | 21 | 20 | 67 |
No | 22 | 17 | 8 | 12 | 59 |
Total | 35 | 30 | 29 | 32 | 126 |
(1)
The percent of Freshman:
(13 /67) *100% = 19.4%
The percent of Sophomore:
(13 /67) *100% = 19.4%
The percent of Junior:
(21/67) *100% = 31.34%
The percent of Senior:
(20/67) *100% = 29.85%
(2)
Hypotheses are:
H0: There is no association between e-textbook satisfaction and academic classification.
Ha: There is an association between e-textbook satisfaction and academic classification.
3:
Expected frequencies will be calculated as follows:
Following table shows the expected frequency:
Satisfied | Freshmen | Sophomore | Junior | Senior | Total |
Yes | 18.611 | 15.952 | 15.421 | 17.016 | 67 |
No | 16.389 | 14.048 | 13.579 | 14.984 | 59 |
Total | 35 | 30 | 29 | 32 | 126 |
Following table shows the calculations for chi square test staistics:
O | E | (O-E)^2/E |
13 | 18.611 | 1.691651228 |
13 | 15.952 | 0.546282849 |
21 | 15.421 | 2.018367227 |
20 | 17.016 | 0.523287259 |
22 | 16.389 | 1.921003173 |
17 | 14.048 | 0.620323462 |
8 | 13.579 | 2.292160027 |
12 | 14.984 | 0.594250934 |
Total | 10.20732616 |
So,
4:
Degree of freedom: df =( number of rows -1)*(number of columns-1) = (2-1)*(4-1)=3
5:
The level of signficance:
6:
The p-value: 0.0169
Excel function used for p-value: "=CHIDIST(10.21,3)"
Since p-value is less than 0.05 so we reject the null hypothesis.
That is we can conclude that there is an association between e-textbook satisfaction and academic classification.