7.2 A random sample of 10 homes in a particular suburb had the following selling prices (in thousands of pounds):

209 256 257 272 275 277 278 285 306 327

a. Check for evidence of nonnormality.

b. Find a point estimate of the population mean that is unbiased and efficient.

c. Use an unbiased estimation procedure to find a point estimate of the variance of the sample mean.

(Hint: Use sample standard deviation to estimate population standard deviation).

d. Use an unbiased estimator to estimate the proportion of homes in this suburb selling for less than

£280,000.