The amounts of electric bills for all households in a city have an approximately normal distribution with a mean of $90 and a standard deviation of $24. Let x be the mean amount of electric bills for a random sample of 16 households selected from the city.

(a) Compute the mean, x, of x. x=$

(b) Compute the standard deviation x of x. x=$

(c) comment on the shape of the sampling distribution of x.