Question

In a study of Math SAT scores done in 2010, the investigators computed the average Math SAT score ( Ai )in each of the 50 states and D.C. and the percentage ( P_i )of high school seniors in each state that took the test that year. They found that the correlation between the variables A and P was r = -0.77.

(a) Does this mean that the test scores were better on average in states where fewer a lower percentage of students took the test? Answer yes or no, and explain your answer briefly.

(b) The average Math SAT score in NY was 515 in 2010, while in Montana, the average score was 603. Does this mean that Montana does a better job preparing students for the Math SAT exam than NY state? Answer yes or no, and explain your reasoning.

Answer 1

A)

a)

When the correlation is negative, it means they are negatively related. When one increases, other decrease and vice-versa.

When a less number of students took the test, then the average was more, This is what can be concluded from a negative correlation.

Yes is the answer.

b)

Here, it doesn't talk about the preparation at all.

If the score is high, it means there were less number of students and vice-versa. Saying that NY students prepared less as compared to Montana student because they got the less average marks won't be appropriate here.

No is the answer.