Making handcrafted pottery generally takes two major

Answer

Step 1 of 2

(a)

We are asked to find the probability that a piece of pottery will be finished within

Let  denote the total time.

Let  denote wheel throwing.

Let  denote wheel firing.

Then, ……….(1)

We need to find

If   are independent, normal random variables

Then we can write,

…….(2)

………(3)

Hence the mean and standard deviation of the total time of wheel throwing and the time of firing using equation

……….(4)

Compare equation (1) and (4), we get

Since total time follows normal distribution, we can write,

Using  table, the area to the left of  is  

Hence the probability that a piece of pottery will be finished within  is