# Question: A graphite manufacturer makes long rolls of flexible graphite to

A graphite manufacturer makes long rolls of flexible graphite to be used to seal components in combustion engines. The specifications state that the mean strength should be 21.2 ounces per square yard with a standard deviation of 0.29. Further specifications state that no roll should have strength less than 20.2 or more than 22.2 ounces per square yard. If there is a defect in terms of the strength of the graphite rolls, the seal will not hold. After the roll is created, a beta scanner takes readings of the basis weight in ounces per square yard. The data is separated into 3 lanes with 20 scans in each lane. A sample consists of one roll from each lane. The results from 20 samples follow:

a) Using the given mean and standard deviation, create an X-bar chart for these samples.

b) Using the given mean and standard deviation, create an R chart for these samples.

c) Is the company’s process for making flexible graphite sheets out of control?

d) Do all the rolls meet the specification limits?

a) Using the given mean and standard deviation, create an X-bar chart for these samples.

b) Using the given mean and standard deviation, create an R chart for these samples.

c) Is the company’s process for making flexible graphite sheets out of control?

d) Do all the rolls meet the specification limits?

**View Solution:**## Answer to relevant Questions

The same graphite manufacturer from Exercise 21 uses an alternative process to make rolls. For this process the data are separated into 10 lanes—a sample consists of one roll from each lane. The results of 25 samples are ...The following data were collected from the number of patient complaints from a small medical service facility over a two-week period. The past year the average number of complaints was 4.57. The management team would like to ...As in Exercise 5, a process to make dental floss produces spools with a desired mean length of 91.4 m (100 yds). The historical standard deviation is 1 cm (0.01 m). If samples of size 5 are taken and measured, a) What is ...For which one of the following situations would Spearman's rho be appropriate? a) The Mohs scale rates the hardness of minerals. If one mineral can scratch another, it is judged to be harder. (Diamond, the hardest mineral, ...A company institutes an exercise break for its workers to see whether this will have any effect on job satisfaction, as measured by a questionnaire that assesses workers’ satisfaction. Scores for 10 randomly selected ...Post your question