Question

Phase Mean SD

Unpacking 4.4 0.5

Assembly 21.2 2.1

Tuning 13.6 2.6

Question: What are the mean and the standard deviation for the total bicycle setup time ? (round to two decimal places as needed.)

Question: A customer decides to buy one of the display models but wants a different color. The shop has one, still in the box. The manager says they can have it ready in half an hour. Do you think the bike will be set up and ready to go as promised ?

Answer: Yes or no and when it will be ready (round to four decimal places as needed).

Answer 1

Given That

Phase Mean SD

Unpacking 4.4 0.5

Assembly 21.2 2.1

Tuning 13.6 2.6

a) Mean for the total bicycle setup time

E(X) = 4.4 + 21.2 + 13.6 = 39.2 min

E(X) = 39.20 min

Standard deviation for the total bicycle setup time

Var (X) = 0.5 + 2.1 + 2.6 = 5.2 min

Standard deviation SD = sqrt(var) = Sqrt (5.2) = 2.28

SD = 2.28

b) Given that

X = Half an hour = 30 min

Z =

Z = -4.035

P(Z < -4.035) = 0.000027

No the bike will not be setup and ready to go as promised