Question

Suppose a large labour union wishes to estimate the mean number of hours per month a union member is absent from work. The union decides to sample n=61 of its members at random and monitor the working time of each of them for 1 month. At the end of the month, the total number of hours absent from work is recorded for each employee. The mean and standard deviation of the sample of workers are 7.18 hours and 3 hours respectively. Estimate the value of mean of the population of workers, µ, the mean number of hours per month union members are absent from work.Fill in the blanks in the following: An estimate of the population mean is___________. The standard error is________________ The distribution is (examples: normal / t12 / chisquare4 / F5,6). For a 99% confidence interval the distributional cut-off is ___________________ It is quite likely that the true mean number of hours per month union members are absent from work is between _________ and ____________, with 99% confidence.

Answer 1

Estimate of the population mean = 7.18

Standard error,

The distribution is t- distribution.

At = 1-0.99 = 0.01 and df = 61-1 = 60, critical value, = 2.66

99% confidence interval:

It is quite likely that the true mean number of hours per month union members are absent from work is between 6.158 and 8.202, with 99% confidence