Bluebook SAT Test Two-Variable Data: Models and Scatterplots 3

Question 1

A linear model predicts plant height (y, cm) from days of growth (x): y = 1.8x + 5. What is the predicted height at day 10?

Accepted Answer

23 cm

Answer

18 cm

Answer

28 cm

Answer

15 cm

Question 2

The correlation coefficient for two variables is r = −0.95. Which statement is true?

Accepted Answer

There is a strong negative linear relationship

Answer

There is a weak negative linear relationship

Answer

There is a strong positive linear relationship

Answer

There is no linear relationship

Question 3

A model for population growth is y = 500(1.04)^x, where x is years. What type of model is this?

Accepted Answer

Exponential

Answer

Linear

Answer

Quadratic

Answer

Inverse

Question 4

A scatterplot of x vs. y has the best-fit line y = −2x + 50. A data point has x = 12, actual y = 30. What is the residual for this point?

Accepted Answer

6

Answer

−6

Answer

4

Answer

−4

Question 5

Which of the following is a correct interpretation of a y-intercept of 40 in a model relating miles driven (x) to fuel cost (y)?

Accepted Answer

When 0 miles are driven, the predicted fuel cost is $40

Answer

Fuel cost increases by $40 per mile

Answer

The maximum fuel cost is $40

Answer

The average miles driven is 40

Question 6

Two variables x and y have the linear model y = 3x − 7. For what value of x does y = 20?

Accepted Answer

9

Answer

13

Answer

7

Answer

27

Question 7

A scatterplot shows values loosely scattered with no discernible direction. What does this suggest about the correlation?

Accepted Answer

The correlation is near zero

Answer

The correlation is near +1

Answer

The correlation is near −1

Answer

The data follows a quadratic pattern