In: Statistics and Probability
The table describes various degrees earned by men and women in foreign languages in 1992.
Bachelor Masters Doctorate Total
Male 3990 971 378 5339
Female 9913 1955 472 12340
Total 13903 2926 850 17679
(a) What percent of females take Doctorate degrees? (b) What percent of Masters degree holders were men? (c) Now test the null hypotheses that obtaining degrees in languages is independent of gender. Give the null and alternative hypothesis, compute the test statistic χ 2 and its degrees of freedom. (d) Is a χ 2 test appropriate for this task? (e) Use the χ 2 table to bound your P-value. What is your conclusion at α = 0.05?
a) percent of females take Doctorate degrees =(472/12340)=0.0382 ~ 3.82%
b)percent of Masters degree holders were men =971/2926=0.3319 ~33.19%
c)null hypothesis: degrees earned and gender are independent
Alternate hypothesis: Ha: degrees earned and gender are dependent
applying chi square test:
Ei=row total*column total/grand total | Bachelors | Masters | Doctors | Total |
male | 4198.66 | 883.64 | 256.70 | 5339 |
female | 9704.34 | 2042.36 | 593.30 | 12340 |
total | 13903 | 2926 | 850 | 17679 |
=(Oi-Ei)2/Ei | Bachelors | Masters | Doctors | Total |
male | 10.3698 | 8.6362 | 57.3219 | 76.328 |
female | 4.4866 | 3.7365 | 24.8008 | 33.024 |
total | 14.856 | 12.373 | 82.123 | 109.352 |
X2 test statistic =109.352
degree of freedom(df) =(rows-1)*(columns-1)= | 2 |
d)Yes as sample is random and expected frequencies are all equal or greater than 5
e)
p value <0.0001
reject HO ' sufficient evidence to conclude that degrees earned and gender are dependent