Answer:
you have to use the protractor tool
Answer:
The 95% confidence interval for the population variance is (8.80, 32.45).
Step-by-step explanation:
The (1 - <em>α</em>)% confidence interval for the population variance is given as follows:

It is provided that:
<em>n</em> = 20
<em>s</em> = 3.9
Confidence level = 95%
⇒ <em>α</em> = 0.05
Compute the critical values of Chi-square:

*Use a Chi-square table.
Compute the 95% confidence interval for the population variance as follows:


Thus, the 95% confidence interval for the population variance is (8.80, 32.45).
Don't know what the question is asking but the are for the skate park would be 3000