Question

a college professor inputs test scores for the first two tests of the semester to determine the correlation. the scatterplot for the test scores is shown, along with the line of best fit. choose the best estimate for r, the correlation coefficient. a -0.70 b -0.30 c 0.30

Explanation:

Step1: Analyze the direction of the line of best fit

The line of best fit in the scatterplot has a positive slope (it goes up from left to right), so the correlation coefficient \( r \) should be positive. This eliminates options A (-0.70) and B (-0.30) which are negative.

Step2: Analyze the strength of the correlation

The points are somewhat clustered around the line of best fit but not extremely tightly. A correlation coefficient of 0.30 (option C) represents a moderate positive correlation, which fits the scatterplot's pattern better than a stronger or weaker (negative) correlation.

Answer:

C. 0.30