9
QuizMultiple Choice

Estimating a Population Proportion

Question 9 • CA-Statistics and Probability B

A producer of 10-ounce bags of pretzels claims that less than 7% of the pretzels in each bag are broken. The 95% confidence interval for the true proportion of broken pretzels in the 10-ounce bags produced by this company is (0.036, 0.067). Is it reasonable to conclude that less than 7% of pretzels in each bag are broken?

Answer
A
Yes, because the entire interval is less than 0.07.
B
Yes, because the center of the interval is 0.0515, which is less than 7%.
C
No, because a different sample might give different results.
D
No, because the interval has many values that are plausible.

Explanation

The 95% confidence interval for the true proportion of broken pretzels is 0.036 to 0.067. Even the interval’s upper endpoint, 0.067, is below 0.07, so all plausible values in the interval are less than 7%. Therefore, it is reasonable to conclude that less than 7% are broken; the correct choice is “Yes, because the entire interval is less than 0.07.”

AI-written and checked against the verified answer.

Previous
Next