The Pizza Distribution authority (PDA) has developed quite a business in Carrboroby delivering pizza orders promptly. PDA guarantees that is pizzas will be deliveredin 30 minutes or less from the time the order was placed, and if the delivery is late,the pizza is free. The time that it takes to deliver each pizza order that is on time isrecorded in the Official Pizza Time Book (OPTB), and the delivery time for thosepizzas that are delivered late is recorded as 30 minutes in the OPTB. Twelve randomentries from the OPTB are listed.

15.3 29.5 30.0 10.1 30.0 19.6 10.8 12.2 14.8 30.0 22.1 18.3

a) Find a point estimate of the mean of the population.

(b) Find a point estimate of the variance of the population.

(c) From what population was this sample drawn?

(d) Can this sample be used to estimate the average time that it takes the PDAto deliver a pizza? Explain