Question

We are testing to see if there is evidence that the proportion of the US citizens who can name the capital city of Brazil is greater than 70%. Choose which sample statistic below that provides the strongest evidence for the claim.

Sample A: 78 successes out of 130

Sample B: 75 successes out of 100

Sample C: 110 successes out of 150

Sample D: 85 successes out of 100

Sample E: 400 successes out of 500

a. Sample C

b. Sample A

c. Sample E

d. Sample B

e. Sample D

Answer 1

We are testing to see if there is evidence that the proportion of US citizens who can name the capital city of Brazil is greater than 70%.

Now, sample A gives 78 successes out of 130. So, the success proportion is

or .

Now, sample B gives 75 successes out of 100. So, the success proportion is

or .

Now, sample C gives 110 successes out of 150. So, the success proportion is

or .

Now, sample D gives 85 successes out of 100. So, the success proportion is

or .

Now, sample E gives 400 successes out of 500. So, the success proportion is

or .

Now, the sample that gives the highest sample proportion is sample D, as it gives 0.85 success proportion.

So, the sample that mostly supports the claim that proportion is greater than 70%, is sample D.

So, the answer is (e) Sample D.