Bluebook SAT Test Two-Variable Data: Models and Scatterplots 7

Question 1

A model for monthly sales (y) based on marketing spend (x, hundreds of dollars) is y = 12x + 80. How many units are sold when $500 is spent on marketing?

Accepted Answer

140

Answer

180

Answer

680

Answer

60

Question 2

The data points (1, 3), (2, 6), (3, 9), (4, 12) lie exactly on a line. What is the slope of the best-fit line?

Accepted Answer

3

Answer

1

Answer

6

Answer

0

Question 3

A dataset has a line of best fit y = −0.5x + 100. When x = 0, what is y? When x = 100, what is y?

Accepted Answer

y = 100 when x = 0; y = 50 when x = 100

Answer

y = 0 when x = 0; y = 50 when x = 100

Answer

y = 100 when x = 0; y = 0 when x = 100

Answer

y = 50 when x = 0; y = 100 when x = 100

Question 4

A researcher collects data and finds the second differences of y are approximately constant. What type of model fits best?

Accepted Answer

Quadratic

Answer

Linear

Answer

Exponential

Answer

Logarithmic

Question 5

The correlation coefficient between hours of TV watched and GPA is r = −0.73. What can you conclude?

Accepted Answer

Students who watch more TV tend to have lower GPAs, and the relationship is moderately strong

Answer

Watching TV causes lower GPAs

Answer

There is a weak positive relationship between TV hours and GPA

Answer

GPA decreases by 0.73 points per hour of TV

Question 6

Using the model y = 1.5x² − 3x + 4, what is y when x = 4?

Accepted Answer

16

Answer

18

Answer

10

Answer

28

Question 7

A line of best fit is drawn through a scatterplot. Most points are very close to the line, and r = 0.98. What does this tell you?

Accepted Answer

A linear model explains most of the variation in the data

Answer

The data has no variation

Answer

The slope is 0.98

Answer

The y-intercept is 0.98