How many parts should be sampled in order to estimate the population mean to within 0.1 millimeter (mm) with 95% confidence? Previous studies of this machine have indicated that the standard deviation of lengths produced by the stamping operation is about 1.8 mm.

At least 1245 parts should be sampled.

Step-by-step explanation:

We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of .

So it is z with a pvalue of , so

Now, find the margin of error M as such

In which is the standard deviation of the population and n is the size of the sample.

How many parts should be sampled in order to estimate the population mean to within 0.1 millimeter (mm) with 95% confidence?

This is at least n parts, in which n is found when

Rouding up

At least 1245 parts should be sampled.

45

step-by-step explanation:

to find a percentage, add a decimal in front and multiply it by the other number.

.25 times 180= 45

answer4 to the second power is 16

and 4 to the third power is 64,