A supplier to automobile manufacturers wants to be sure that the leak rate (in cubic centimeters per second) of transmission oil coolers (TOCs) meets the established specification limits. A random sample of 10 TOCs is tested, and the leak rates are shown below.
0.044 0.042 0.054 0.044 0.052 0.055 0.044 0.059 0.049 0.054
a. Is there evidence that the data are not normally distributed?
b. Find a minimum variance unbiased point estimate of the population mean.
c. Use an unbiased estimation procedure to find a point estimate of the variance of the sample mean.