# Computing correlation coefficients

Compute the correlation coefficient for the data below:

X 4 -1 1 3 4

Y 3 -1 -2 3 1

A) -0.082 B) 0.013 C) 0.286 D) 0.77

Compute the correlation coefficient for the data below.

X 2 1 0 3

Y 4 2 8 1

A) -0.142 B) 0.429 C) -0.792 D) -0.349

Ten pairs of points yielded a correlation coefficient r = 0.79. If ? = 0.05, which of thefollowing statements is correct if H0:? ? = 0? (Do not calculate a t-value.)

A) Because 0.79 is greater than 0.632, the null hypothesis is rejected.

B) Because 0.79 is greater than 0.602, the null hypothesis is not rejected.

C) Because 0.79 is greater than 0.632, the null hypothesis is not rejected.

D) There is no correlation between the variables

Correlation coefficient computed for n = 18 and ? = 0.10 is r = 0.692. Using the t-test for

the correlation coefficient, what are the critical values?

A) ±1.734 B) ±2.120 C) ±1.746 D) ±2.101

Compute the slope of the regression line for the data below.

X 3 0 3 5 3

Y 7 4 -2 2 -3

A) -4.13 B) -0.5 C) -0.72 D) 1.20

Compute the intercept of the regression line for the data below.

X -3 1 5 8

Y 3 2 -3 0

A) 2.22 B) 1.60 C) 2.93 D) 1.77

For a prediction value of y' from a specific value of x, which of the following contribute to

the prediction error?

A) The error in estimating the slope

B) The error in estimating the intercept

C) The standard error of the estimate

D) All of the above

In a regression model y' = -10 + 2x, if the value of x changes by -6, then the actual value of

y will

A) decrease by 6 B) increase by 3 C) decrease by 12 D) cannot be determined

In a regression model y' = -8 + 5x, if the x value increases by 2, then the predicted value for y will change by

A) 10 B) -8 C) 8 D) -10

Compute the standard error of the estimate for the data below

X 3 -2 2 5 10

Y 4 6 -2 0 -3

A) 2.89 B) 1.96 C) 0.87 D) 2.36

https://brainmass.com/statistics/correlation/computing-correlation-coefficients-477344

#### Solution Preview

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Please need help with correlation

Compute the correlation coefficient for the data below.

X 4 -1 1 3 4

Y 3 -1 -2 3 1

A) -0.082

B) 0.013

C) 0.286

D) 0.77

Compute the correlation coefficient for the data below.

X 2 1 0 3

Y 4 2 8 1

A) -0.142

B) 0.429

C) -0.792

D) -0.349

Ten pairs of points yielded a correlation coefficient r = 0.79. If ? = 0.05, which of the following statements is correct if H0:€ ? = 0? (Do not calculate a t-value.) ...

#### Solution Summary

The following posting helps with problems that involve computing the correlation coefficients for various datasets.

Compute the Covariance and Coefficient of Correlation

30. a. Compute the covariance for X and Y in Exercise 22 (see attachment)

b. Compute ρ (correlation coefficient) for X and Y in the same exercise.

Please see the attached file for the fully formatted problems.

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