Answer:




(e) There is sufficient evidence to reject the claim that the mean etch rate is the same for both solutions

Explanation:
Given
Solutions 1 and 2
Solving (a): Mean of solution 1
For Solution 1, we have the following data:

The sample mean is calculated as:

Where

So, we have:



Solving (b): Mean of Solution 2
For Solution 1, we have the following data:

The sample mean is calculated as:

Where

So, we have:



Solving (c): Sample Standard Deviation of solution 1
This is calculated as:

This gives:




--- approximated
Solving (d): Sample Standard Deviation of solution 2
This is calculated as:

So, we have:





Solving (e): Test the hypothesis

Start by calculating pooled standard deviation





Calculate test statistic






Calculate the degree of freedom



The p value is the in the column title of the student t distribution in row 18

The p value is less than the significance level (0.05).
i.e.

<em>So: Reject the null hypothesis</em>
Solving (f): 95% two-sided confidence interval

Calculate the degree of freedom



Calculate 




Using student t distribution

Calculate margin of error (E)




The boundaries of the confidence are:
The confidence interval is:
