Scatterplot Regression Review

Determine if the statement is true or false. If a statement is false, correct it so that it will be true. A correlation coefficient of -0.68 would mean that as the value of x increases, the value of y increases.

• True

• False, A correlation coefficient of -0.68 would mean that as the value of x increases, the value of y decreases.

• False, A correlation coefficient of -0.68 would mean that 68% of the variation of y is accounted for by the linear model with x.

Given data about the hours spent online and the test score, the mean for hours online was 4.5 with a standard deviation of 2.84. The mean for test score was 75.67 with a standard deviation of 13.92. The correlation was -0.83. Find the equation of the least squares regression line for predicting test score from hours spent online.

The ages (in years) and the number of hours of sleep in one night for 7 adults is shown. Find the correlation.

• -0.95

• 0.95

• 0.90

• -0.90

The ages (in years) and the number of hours of sleep in one night for 7 adults is shown. Find the coefficient of determination (r^2).

• -0.95

• 0.95

• 0.90

• -0.90

The ages (in years) and the number of hours of sleep in one night for 7 adults is shown. What is the equation of the least squares regression line?

The ages (in years) and the number of hours of sleep in one night for 7 adults is shown. Describe the association (sketch a scatterplot first!)

• positive, linear, strong

• negative, linear, strong

• negative, linear, moderate

• positive, non-linear, weak

The ages (in years) and the number of hours of sleep in one night for 7 adults is shown. What percent of the variability of hours of sleep is described by the linear model with age?

• 95%

• 90%

• 9%

• 10%

The ages (in years) and the number of hours of sleep in one night for 7 adults is shown. Given  , predict the hours of sleep for someone that is 40 years old.

• 6.85 hours

• -14.05 hours

• -6.85 hours

• 14.05 hours

The ages (in years) and the number of hours of sleep in one night for 7 adults is shown. Given

y = -0.09x + 10.45, predict the hours of sleep for someone that is 68 years old.

• 16.57 hours

• -4.33 hours

• -16.57 hours

• 4.33 hours

The ages (in years) and the number of hours of sleep in one night for 7 adults is shown. Given

y = -0.09x + 10.45, predict the hours of sleep for someone that is 87 years old.

• 2.62 hours

• -18.28 hours

• -2.62 hours

• 18.28 hours