In: Statistics and Probability
#1) An researcher wishes to see if the primary way people obtain information is independent of their highest level of education. A survey of 400 high school and college graduates yielded the following information. At the a = 0.05 significance level, test the claim that the way people obtained information is independent of their education level.
TV Newspaper Other sources
High school 163 30 52
College 37 65 53
- A clear statement of hypotheses
- An indication of the test being used
- Statement of the test statistic and either
p-value (or appropriate critical value)
- Explicit statement of the statistical decision,
along with a reason
- A specific conclusion based on the statistical
decision
Ans:
Chi square test for independence:
H0: The way people obtained information is independent of their education level.
Ha:The way people obtained information is not independent of their education level.
Observed(fo) | ||||
TV | News paper | Others | Total | |
High school | 163 | 30 | 52 | 245 |
College | 37 | 65 | 53 | 155 |
Total | 200 | 95 | 105 | 400 |
Expected(fe) | ||||
TV | News paper | Others | Total | |
High school | 122.5 | 58.1875 | 64.3125 | 245 |
College | 77.5 | 36.8125 | 40.6875 | 155 |
Total | 200 | 95 | 105 | 400 |
Chi square=(fo-fe)^2/fe | ||||
TV | News paper | Others | Total | |
High school | 13.390 | 13.655 | 2.357 | 29.402 |
College | 21.165 | 21.583 | 3.726 | 46.474 |
Total | 34.554 | 35.238 | 6.083 | 75.875 |
Test statistic:
Chi square=75.875
df=(2-1)*(3-1)=2
p-value=CHIDIST(75.875,2)=0.0000
As,p-value<0.05,we reject the null hypothesis.
There is sufficient evidence to reject the claim that the way people obtained information is independent of their education level.