In: Statistics and Probability
Do people think that diversity in a large population is healthy or damaging? At one college, responses of a randomly selected group of students found that 10 students majoring in behavioral sciences thought diversity healthy and 3 thought it damaging. In the natural sciences, 4 thought diversity healthy and 8 thought it damaging. In the arts, 18 thought diversity healthy and 7 thought it damaging. In the languages, 6 thought diversity healthy and 7 thought it damaging. Finally, in the field of history, 4 students thought diversity healthy and 9 thought it damaging. Do these results suggest that opinions about diversity vary over different majors? (Use the .05 significance level.)
Choose the appropriate test and use the five steps of hypothesis testing!
Step 1:
H0: Null Hypothesis: Opinions about diversity do not vary over different majors
HA: Alternative Hypothesis: Opinions about diversity vary over different majors (Claim)
Step 2:
Observed Frequencies:
Healthy | Damaging | Total | |
behavioral sciences | 10 | 3 | 13 |
the natural sciences | 4 | 8 | 12 |
arts | 18 | 7 | 25 |
languages | 6 | 7 | 13 |
history | 4 | 9 | 13 |
Total | 42 | 34 | 76 |
Expected Frequencies:
Healthy | Damaging | Total | |
behavioral sciences | 42X13/76=7.184 | 34X13/76=5.816 | 13 |
the natural sciences | 42X12/76=6.632 | 34X12/76=5.368 | 12 |
arts | 42X25/76=13.816 | 34X25/76=11.184 | 25 |
languages | 42X13/76=7.184 | 34X13/76=5.816 | 13 |
history | 42X13/76=7.184 | 34X13/76=5.816 | 13 |
Total | 42 | 34 | 76 |
Test Statistic (Chi Square) is got as follows:
Observed (O) | Expected (E) | (O - E)2/E |
10 | 7.184 | 1.104 |
3 | 5.816 | 1.36 |
4 | 6.632 | 1.044 |
8 | 5.368 | 1.29 |
18 | 13.816 | 1.267 |
7 | 11.184 | 1.565 |
6 | 7.184 | 0.195 |
7 | 5.816 | 0.241 |
4 | 7.184 | 1.411 |
9 | 5.816 | 1.743 |
Total = Test Statistic (Chi Square) = | 11.225 |
So,
Test Statistic (Chi Square) = 11.225
Step 3:
df = (5 - 1) X (2 - 1) = 4
alpha = 0.05
From Table,
critical value of chi square = 9.88
Step 4:
Since calculated value of chi square = 11.225 is greater than
critical value of chi square = 9.88, the difference is significant.
Reject null hypothesis.
Conclusion:
The data support th claim that opinions about diversity vary over
different majors.
Step 5:
By Technology,
p - value = 0.0242
Since p - value = 0.0242 is less than alpha = 0.05, the difference is significant. Reject null hypothesis.
Conclusion:
The data support th claim that opinions about diversity vary over
different majors.