Question

A 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 0.4 ounce, what should be the mean setting so that an 8-ounce cup will overflow only 0.5% of the time?

Answer 1

The mean will be calculates as follows; from the formula of z-score we shall have:
z=(x-μ)/σ
the z-score associated with 0.5% is 0
thus
0=
(8-μ)/0.4=0
solving for x we get:
μ=9 

Answer: μ=9