Bluebook SAT Test Two-Variable Data: Models and Scatterplots 6

Question 1

The linear model for height (y, inches) based on age (x, years, ages 2–10) is y = 2.5x + 32. By how much does the model predict height increases per year?

Accepted Answer

2.5 inches

Answer

32 inches

Answer

34.5 inches

Answer

30 inches

Question 2

A best-fit line passes through (0, 12) and (4, 28). What is the equation of this line?

Accepted Answer

y = 4x + 12

Answer

y = 12x + 4

Answer

y = 4x − 12

Answer

y = 3x + 12

Question 3

A scatterplot shows the following points: (1, 2), (2, 8), (3, 18), (4, 32). Which model best fits these data?

Accepted Answer

Quadratic

Answer

Linear

Answer

Exponential

Answer

Constant

Question 4

What does a residual plot that shows a curved pattern (not random scatter) indicate?

Accepted Answer

The chosen model is not an appropriate fit; a different model should be tried

Answer

The data has no pattern

Answer

The model is a perfect fit

Answer

The slope should be increased

Question 5

A scatterplot of x and y shows r = 0.60. Which statement is most accurate?

Accepted Answer

There is a moderate positive linear relationship between x and y

Answer

60% of x values are positive

Answer

x causes y with 60% certainty

Answer

The slope of the best-fit line is 0.60

Question 6

A model y = 2x + 5 predicts production costs. An actual data point is (6, 22). By how much does the model overpredict or underpredict?

Accepted Answer

The model overpredicts by 5

Answer

The model underpredicts by 5

Answer

The model overpredicts by 6

Answer

The model matches exactly

Question 7

Two scatterplots: Plot A has r = 0.95 and Plot B has r = 0.40. Which plot shows points closer to the line of best fit?

Accepted Answer

Plot A

Answer

Plot B

Answer

Both are equally close

Answer

Cannot be determined