Question

hello

i have this problem that i need to be solved:

Twenty observations on etch uniformity on silicon wafers are taken during a qualification experiment for a plasma etcher. The data are as follows:

4.54    4.86   3.19 3.34    4.71

5.55   4.83   4.11 3.57 5.11

4.77   3.94   5.13 2.47 4.2

3.28    3.31    2.72     3.4    2.4

Construct a 95 percent confidence interval estimate of σ².

Lower Limit = ____________

Upper Limit = ____________

Answer 1

Solution:

The 95% confidence interval estimate of is:

Where:

is the sample variance of the given data.

is the sample size

Therefore, the 95% confidence interval is:

Lower Limit = 0.516

Upper Limit = 1.902