Question

A company is
interested in estimating *μ*, the mean number of days of
sick leave taken by its employees. Their statistician randomly
selects 100 personnel files and notes the number of sick days taken
by each employee. The sample mean is 12.2 days, and the sample
standard deviation is 10 days. How many personnel files would the
statistician have to select in order to estimate *μ* to
within 2 days with a 99 percent confidence interval?

*Note: Sigma
Unknown*

136 |
||

13 |
||

165 |
||

173 |
||

2 |

Answer #1

Sample standard deviation =10

Margin of error =E=2

Level of significance =0.01

Z critical value is (by using Z table)=2.576

Sample size formula is

=165.89

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