Question

Suppose that a random sample of 50 bottles of a particular brand of cough syrup is selected and the alcohol content of each bottle is determined. Let m denote the average alcohol content for the population of all bottles of the brand under study. Suppose that the resulting 95% confidence interval is (7.8, 9.4). a. Would a 90% confidence interval calculated from this same sample have been narrower or wider than the given interval

Answer 1

Answer:

95% confidence interval will be narrower.

Step-by-step explanation:

We are given the following in the question:

Sample size, n = 50

95% confidence interval for average alcohol content:

$(7.8, 9.4)$

a) 90% confidence interval

• If we calculate a 90% confidence interval, then the confidence interval become narrower because we decreased the confidence percentage.

• This would decrease the margin of error.

• Hence, the confidence interval become narrower.