In: Statistics and Probability
Is intelligence related to deciding to go out on a
date? Below is data for males and females from a
study on speed dating
Male
Decision |
||
Intelligence Rating |
Date |
No Date |
0-8 |
66 |
53 |
8-10 |
58 |
91 |
Females
Decision |
||
Intelligence Rating |
Date |
No Date |
0-8 |
57 |
34 |
8-10 |
90 |
92 |
1. What type of hypothesis test would you use to see if
intelligence and deciding on a date are related for males?
a. Goodness of Fit
b. Test of Heterogeneity
c. Test of Independence
2. What type of hypothesis test would you use to see if
intelligence and deciding on a date are related for females?
a. Goodness of Fit
b. Test of Heterogeneity
c. Test of Independence
3. Can you conduct the tests with data as given?
a. Yes, because each cell has a positive number in it
b. Yes, because each cell has a large enough value
c. No, since totals are not given to us
d. No, since there cells with values less than five
4. What are the p-values for the tests for
a. Males
b. Females
5. Are intelligence and deciding on a date related?
a. No for males, No for females
b. No for males, Yes for females
c. Yes for males, No for females
d. Yes for males, Yes for females
Ans:
1) Test of Independence
2) Test of Independence
3)Yes, because each cell has a large enough value(expected count>5)
4)Males:
Observed count(fo) | |||
Intelligence | Date | No Date | |
Rating | Total | ||
0-8 | 66 | 53 | 119 |
8-10 | 58 | 91 | 149 |
Total= | 124 | 144 | 268 |
Expected count(fe) | |||
Intelligence | Date | No Date | |
Rating | Total | ||
0-8 | 55.06 | 63.94 | 119 |
8-10 | 68.94 | 80.06 | 149 |
Total= | 124 | 144 | 268 |
chi square=(fo-fe)^2/fe | |||
Intelligence | Date | No Date | |
Rating | Total | ||
0-8 | 2.17 | 1.87 | 4.05 |
8-10 | 1.74 | 1.50 | 3.23 |
Total= | 3.91 | 3.37 | 7.28 |
Test statistic:
Chi square score=7.28
df=(2-1)*(2-1)=1
p-value=CHIDIST(7.28,1)=0.0070
Females:
Observed count(fo) | |||
Intelligence | Date | No Date | |
Rating | Total | ||
0-8 | 57 | 34 | 91 |
8-10 | 90 | 92 | 182 |
Total= | 147 | 126 | 273 |
Expected count(fe) | |||
Intelligence | Date | No Date | |
Rating | Total | ||
0-8 | 49.00 | 42.00 | 91 |
8-10 | 98.00 | 84.00 | 182 |
Total= | 147 | 126 | 273 |
chi square=(fo-fe)^2/fe | |||
Intelligence | Date | No Date | |
Rating | Total | ||
0-8 | 1.31 | 1.52 | 2.83 |
8-10 | 0.65 | 0.76 | 1.41 |
Total= | 1.96 | 2.29 | 4.24 |
Test statistic:
Chi square score=4.24
df=(2-1)*(2-1)=1
p-value=CHIDIST(4.24,1)=0.0394
5)Assume significance level=0.05
For,Males:
As,p-value<0.05,we reject null hypothesis and we can conclude that intelligence and deciding on a date are related.
For,Females:
As,p-value<0.05,we reject null hypothesis and we can conclude that intelligence and deciding on a date are related.
So,option d is correct.(Yes for males, Yes for females)