Problem 25SE

Refer to Exercise 24.Asample of six repair records for a different type of component was drawn. The repair costs, in dollars, were as follows.

Would it be appropriate to compute a 95% confidence interval for the population standard deviation of the costs? If so, compute it. If not, explain why not.

Exercise 24

A sample of eight repair records for a certain fiber-optic component was drawn, and the cost of each repair, in dollars, was recorded. The results were

Assume the population of repair records is normal. Find a 95% confidence interval for the population standard deviation.

Solution

Step 1 of 1

Here we have to tell whether we can find the 95% confidence for the population standard deviation interval for the given 6 sample values

The given values are 93, 97, 27, 79, 81, 87

For finding that we have to draw the scatter plot

For plotting that we have to follow the steps

1. Select the data

2. Select Insert from the menu bar

3. Select Scatter plot

The we will get the scatter plot

From the diagram the values are not forming like normal curve

So the values are not following the normal distribution

Hence we can’t find the 95% confidence interval for the population standard deviation for the given 6 sample values