In: Statistics and Probability
Female |
Male |
Total |
|
Accounting |
68 |
56 |
124 |
Administration |
91 |
40 |
131 |
Economics |
5 |
6 |
11 |
Finance |
61 |
59 |
120 |
Other |
39 |
25 |
64 |
Total |
264 |
186 |
450 |
Solution:
Given: At a Midwestern University the 450 students in the Business School were classified according to their major within the business school and their gender.
Female | Male | Total | |
Accounting | 68 | 56 | 124 |
Administration | 91 | 40 | 131 |
Economics | 5 | 6 | 11 |
Finance | 61 | 59 | 120 |
Other | 39 | 25 | 64 |
Total | 264 | 186 | N = 450 |
Part a) Complete a table for marginal distribution.
We divide each frequency by N = 450 in above table.
Major Gender | Female | Male | Marginal distribution of Major |
Accounting | 0.151111 | 0.124444 | 0.275556 |
Administration | 0.202222 | 0.088889 | 0.291111 |
Economics | 0.011111 | 0.013333 | 0.024444 |
Finance | 0.135556 | 0.131111 | 0.266667 |
Other | 0.086667 | 0.055556 | 0.142222 |
Marginal distribution of Gender | 0.586667 | 0.413333 | 1 |
Part b) Complete a table for Conditional distribution
Conditional distribution Major Given Gender:
Formula for conditional probability is:
Then
Similarly we find all conditional probabilities:
P(Major |Female) | P(Major |Male) | ||
P(Accounting | Female)= | 0.257576 | P(Accounting | Male)= | 0.301075 |
P(Administration | Female)= | 0.344697 | P(Administration | Male)= | 0.215054 |
P(Economics | Female)= | 0.018939 | P(Economics | Male)= | 0.032258 |
P(Finance | Female)= | 0.231061 | P(Finance | Male)= | 0.317204 |
P(Other | Female)= | 0.147727 | P(Other | Male)= | 0.134409 |
Conditional distribution Gender given Major:.
Similarly we find all probabilities:
P(Female | Major) | P(Male |Major) | ||
P(Female|Accounting)= | 0.548387 | P(Male|Accounting)= | 0.451613 |
P(Female|Administration)= | 0.694656 | P(Male|Administration)= | 0.305344 |
P(Female|Economics)= | 0.454545 | P(Male|Economics)= | 0.545455 |
P(Female|Finance)= | 0.508333 | P(Male|Finance)= | 0.491667 |
P(Female|Other)= | 0.609375 | P(Male|Other)= | 0.390625 |