As an Aid to the Establishment of Personnel Requirements, the Director

Multiple Choice

As an aid to the establishment of personnel requirements, 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, $\bar { X } = 396 \text { and } S = 100$ . Which of the following assumptions is necessary in
Order for a confidence interval to be valid?

A) The population sampled from has an approximate normal distribution.
B) The population sampled from has an approximate t distribution.
C) The mean of the sample equals the mean of the population.
D) None of these assumptions are necessary.