Answer
a. 140
b. 9999
c. .8078
d. No
Work Step by Step
a. We find that the mean weight is:
$=\frac{3500}{25}=140\ Ibs$
b. We find that the z-score is:
$z = \frac{(140)-(182.9)}{40.8/(\sqrt{25})}=-5.257$
This is greater than -3.5, so it follows that the probability is .9999.
c. We find the z score:
$z=\frac{175-182.9}{40.8/\sqrt{20}}=-.87$
Consulting the table of z-scores, we see that the probability is .8078.
d. No, this is still not safe. You want a much higher probability for safety regulations.
