The length of slots machined in metal pieces by a milling machine is expected to be approximately normally distributed with a mean of 5.2 inches and a standard deviation of .08 inches. If you measure the slot length of a random sample of 20 metal pieces, what is the standard deviation of the sampling distribution of the sample mean?

You must use the best approximate values in the normal distribution tables. Do not average table values.

Select one:

a.

0.063

b.

5.2

c.

0.08

d.

None of the answers are correct

e.

0.018