# Question

How large a sample is required to obtain a natural tolerance interval that has probability 0.90 of containing 95% of the distribution? After the data are collected, how would you construct the interval?

## Answer to relevant Questions

A random sample of n= 40 pipe sections resulted in a mean wall thickness of 0.1264 in. and a standard deviation of 0.0003 in. We assume that wall thickness is normally distributed. (a) Between what limits can we say with 95% ...A process is in statistical control with x = 199 and R = 3.5. The control chart uses a sample size of n= 4. Specifications are at 200 ± 8. The quality characteristic is normally distributed. USL = 200 + 8 = 208; LSL = 200 ...Consider the hospital emergency room waiting time data in Exercise 8.16. Set up an EWMA control chart for monitoring this process using = 0.2. Does the process seem to be in statistical control? p50 4.55; p84 ...Consider a standardized two-sided CUSUM with k = 0.2 and h=8. Use Siegmund’s procedure to evaluate the in-control ARL performance of this scheme. Find ARL1 for * = 0.5. In control ARL performance: (a) Add a headstart feature to the CUSUM in Exercise 9.1. (b) Use a combined Shewhart-CUSUM scheme on the data in Exercise 9.1. Interpret the results of both charts.Post your question

0