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%.
Solve for r.
Use distributive property.
4/4r - 8/4 = r - 2
4/4 can be written as 1 and -8/4 can be written as -2.
r - 2 = r - 2
You have an infinite amount of solutions.
Hope this helps!
