Question

The results of a survey show that the percent of students in an Algebra II class who want to have their grades scored on a curve is in the interval [48.2, 56.4].

a. What is the point estimate for the percent who want to have their grades scored on a curve?
b. What is the poll’s margin of error?
c. Do you think their class should have their grades scored on a curve? Which statistic influenced your answer the most? Explain.

Answer 1

a. The point estimate would be the average of the interval boundaries, which is the average of 48.2 and 56.4. This gives a point estimate of 52.3%.
b. The margin of error is the distance from either interval boundary to the point estimate. 56.4 - 52.3 = 4.1%.
c. Assuming this is solely going to be based on the class' decision, their grades should be scored on a curve. Although the margin of error is high and this seems to not have a significant distance from 50%, there is no "middle ground" in this option. We must either grade on a curve or not, and if we must choose one, we have to use to point estimate that is just slightly above 50%.