A random sample of repair times, in hours, was taken for an electronic component. The 4 observed times are shown below.
1.3
1.7
1.4
1.8
Calculate unbiased estimates of the mean and the variance of the population of repair times for this electronic component.
The population standard deviation of the repair times for this electronic component is known to be 0.5 hours.
An estimate of the population mean is required to be within 0.1 hours of its true value with a probability of at least 0.99