Answer:
95% Confidence interval for the variance:

95% Confidence interval for the standard deviation:

Step-by-step explanation:
We have to calculate a 95% confidence interval for the standard deviation σ and the variance σ².
The sample, of size n=8, has a standard deviation of s=2.89 miles.
Then, the variance of the sample is

The confidence interval for the variance is:

The critical values for the Chi-square distribution for a 95% confidence (α=0.05) interval are:

Then, the confidence interval can be calculated as:

If we calculate the square root for each bound we will have the confidence interval for the standard deviation:

Answer:
its too small to see
Step-by-step explanation:
ANSWER

EXPLANATION
The given expression is

We identity and remove the perfect squares to obtain

We now observe that, the three terms are all similar.
We combine the similar terms to get:

I think the answer is: she got 36 right and you would have 2 rectangles for the wrong answers in the tape diagram and 9 for the right.
hope I helped...