Question

practice problems

1. select all the values for r that indicate a positive slope for the line of best fit.

□ 1
□ -1
□ 0.5
□ -0.5
□ 0
□ 0.8
□ -0.8

1. the correlation coefficient, r, is given for several different data sets. which value indicates the strongest correlation?

a. 0.01
b. -0.34
c. -0.82
d. -0.95

Explanation:

Step1: Recall correlation - slope relationship

A positive - valued correlation coefficient \(r\) indicates a positive slope for the line of best fit.

Step2: Analyze values for positive slope in question 1

Positive values of \(r\) are \(1\), \(0.5\), \(0.8\).

Step3: Recall strength of correlation

The strength of the correlation is determined by the absolute value of the correlation coefficient \(|r|\). The closer \(|r|\) is to \(1\), the stronger the correlation.

Step4: Analyze values for strongest correlation in question 2

For \(A\), \(|0.01| = 0.01\); for \(B\), \(|- 0.34|=0.34\); for \(C\), \(|-0.82| = 0.82\); for \(D\), \(|-0.95|=0.95\). Since \(0.95\) is closest to \(1\), \(D\) indicates the strongest correlation.

Answer:

1. 1, 0.5, 0.8
2. D. -0.95