A local bus company is planning a new route to serve four housing subdivisions. Random samples of households are taken from each subdivision and sample members are asked to rate on a scale from 1 (strongly opposed) to 5 (strongly in favor) their reaction to the pro- posed service. The results are summarized in the accompany table.

(a) Find a 90% confidence interval for the mean reaction of households in subdivision I.

(b) Using an unbiased estimation procedure, estimate the mean reaction of all households to be served by the new route.

(c) Find 90% and 95% confidence intervals for the mean reaction of all households to be served by the new route.