Question

coffee machine can be adjusted to deliver any fixed number of ounces of coffee. If the machine has a standard deviation in delivery equal to 0.2 ounce, what should be the mean setting so that an 8-ounce cup will overflow only 1.0% of the time?

Question 9 options:

	7.9
	8.2
	7.5
	7.1

Answer 1

Solution :

mean = $\mu$ = 8

standard deviation = $\sigma$ = 0.2

Using standard normal table,

P(Z < z) = 1%

P(Z < -2.326) = 0.01

z = -2.326

Using z-score formula,

x = z * $\sigma$ + $\mu$

x = -2.326 * 0.2 + 8 = 7.5

Time = 7.5