In: Statistics and Probability
2. A team of market researchers conducted a study involving 200 inhabitants of the United States to determine what people fear most. The gender of each person polled was noted, and then each was asked which of the following was his or her greatest fear: speaking before a group, heights, bugs/insects, financial problems, sickness/death, and other. The results of the poll are given in the table. Do the data provide sufficient evidence to indicate a relationship between gender and greatest fear? Test at the a=.05 level.
Speaking before a group |
Heights |
Bugs/Insects |
Financial Problems |
Sickness/death |
Other |
|
Male |
21 |
10 |
7 |
23 |
15 |
21 |
Female |
16 |
22 |
15 |
9 |
18 |
23 |
Claim: There is a relationship between gender and greatest fear.
The null and alternative hypothesis is
H0: There is NO relationship between gender and greatest fear.
H1: There is a relationship between gender and greatest fear.
Level of significance = 0.05
Test statistic is
O: Observed frequency
E: Expected frequency.
E = ( Row total*Column total) / Grand total
Speaking | Heights | Bugs | Financial | sickness | other | Total | |
Male | 21 | 10 | 7 | 23 | 15 | 21 | 97 |
Female | 16 | 22 | 15 | 9 | 18 | 23 | 103 |
Total | 37 | 32 | 22 | 32 | 33 | 44 | 200 |
O | E | (O-E) | (O-E)^2 | (O-E)^2/E |
21 | 17.945 | 3.055 | 9.333025 | 0.520091 |
10 | 15.52 | -5.52 | 30.4704 | 1.963299 |
7 | 10.67 | -3.67 | 13.4689 | 1.262315 |
23 | 15.52 | 7.48 | 55.9504 | 3.605052 |
15 | 16.005 | -1.005 | 1.010025 | 0.063107 |
21 | 21.34 | -0.34 | 0.1156 | 0.005417 |
16 | 19.055 | -3.055 | 9.333025 | 0.489794 |
22 | 16.48 | 5.52 | 30.4704 | 1.848932 |
15 | 11.33 | 3.67 | 13.4689 | 1.188782 |
9 | 16.48 | -7.48 | 55.9504 | 3.395049 |
18 | 16.995 | 1.005 | 1.010025 | 0.059431 |
23 | 22.66 | 0.34 | 0.1156 | 0.005102 |
Total | 14.41 |
Degrees of freedom = ( Number of rows - 1 ) * ( Number of column - 1) = ( 2 - 1) * (6 - 1) = 1 * 5 = 5
Critical value = 11.070
Test statistic > critical value we reject null hypothesis.
Conclusion:
There is a relationship between gender and greatest fear.