Question

Ten engineering schools in a country were surveyed. The sample contained 250 electrical​ engineers, 100 being​ women; 200 chemical​ engineers, 50 being women. Compute a 90​% confidence interval for the difference between the proportions of women in these two fields of engineering. Is there a significant difference between the two​ proportions?

Let p1 be the population proportion of electrical engineers that are women in the schools that were surveyed and let p2 be the population proportion of chemical engineers that are women in the schools that were surveyed.

The 90​% confidence interval is __<p 1 - p 2<___

Answer 1

n1 = 250
n2 = 200


Lower Limit =
upper Limit =
90% Confidence interval is ( 0.0783 , 0.2217 )
( 0.0783 < ( P1 - P2 ) < 0.2217 )

Is there a significant difference between the two​ proportions?

Since value 0 does not lies in the interval, hence we can say that there is difference between the two proportion at 10% level of significance.