Ultimate access to all questions.
Explanation:
With a known variance, the 95% confidence interval is constructed as . So the analyst knew $33.23 = 30 + 1.96 \frac{\sigma}{\sqrt{100}}\sigma$ provides 16.48.
(Book 2, Module 17.1, LO 17.d)
Based on a sample size of 100 and a sample mean of $30, a risk analyst estimates a 95% confidence interval for the mean weekly soft drink expenditures of students at a local college. His estimate of the confidence interval is $26.77 to $33.23. Since the analyst knew the standard deviation beforehand, the confidence interval was based on a standard deviation closest to:
A
1.65.
B
6.59.
C
11.53.
D
16.48.
No comments yet.