PLEASE HELP me solve the following problem:

A computer diskette manufacturer is concerned that some diskettes have bad sectors that would cause a diskette to hold less information that it was intended to hold. In the past, only 5% of these diskettes have had bad sectors. If the company wishes to use 99.7% control limits based on samples of size 500, what would these limits be. LCL = _____ and UCL = _____??? Thanks.

2 answers

Lower limits = mean - 3(sd/√n)
Upper limits = mean + 3(sd/√n)

mean = np
sd = √npq

n = 500
p = .05
q = 1 - p

Calculate the lower and upper limits using the mean, standard devation, and sample size.

I hope this helps.
THANK YOU, MathGuru, for your help!