See explanation. You didn't specify on whether the problem asks for a fraction or decimal, so I put both decimal and fraction.
Step-by-step explanation:
First we answer a:
Total amount of people polled is 291. Number of people who wear glasses is:
Divide to get the proportion: which is also equal to: 0.4295532646
Then we answer b:
b asks for the proportion of all above average readers who wear glasses, so the total number would be: . The number of above average readers who wear glasses is then 48.
We then get the proportion: , which is also equal to 0.6575342466.
This is not an isosceles triangle because there are different angle measurements. The rule of an isosceles triangle is that it must always have two equal sides and angles.