Question

A historian working as a consultant for a Hollywood World War II film wants to know if the proportion of planes built by the Allies that were shot down was different than the proportion of planes built by the Axis that were shot down. He randomly takes a sample of 200 planes from Allies production and flight records and finds that 36% were shot down. In a random sample of Axis planes, 40% were shot down. Provide a 95% confidence interval.

Two dependent means

Two independent means

Two-sample proportion

One-sample proportion

cannot do, assumptions violated

One-sample mean

Answer 1

Two-sample proportion

Solution:

For the given scenario, we have to compare the two population proportions.

The null and alternative hypotheses for this test are given as below:

Null hypothesis: H0: the proportion of planes built by the Allies that were shot down was same as the proportion of planes built by the Axis that were shot down.

Alternative hypothesis: Ha: the proportion of planes built by the Allies that were shot down was different than the proportion of planes built by the Axis that were shot down.