The Director of a Hospital Wishes to Estimate the Mean $\bar { x } = 19.8$

Multiple Choice

The director of a hospital wishes to estimate the mean number of people who are admitted to the emergency room during a 24-hour period. The director randomly selects 64 different 24-hour periods and determines the number of admissions for each. For this sample, $\bar { x } = 19.8$ and $s ^ { 2 } = 4$ . If the director wishes to estimate the mean number of admissions per 24-hour period to within 1 admission with $90 \%$ reliability, what is the minimum sample size she should use?

A) 7
B) 27
C) 44
D) 11