unit 11 check in - scatter plots and data

1. Jeremiah conducts a survey and finds that as the first variable in his survey decreases, the second variable increases. What type of association is there between the two variables?

• A. Positive association

• B. Negative association

• C. No association

• D. There is not enough information to tell.

2. Which best describes the scatterplot below?

• A. Negative association; linear

• B. Negative association; non-linear

• C. Positive association; linear

• D. Positive association; non-linear

3. How can you determine if the association on a scatter plot is strong or weak?

• A. By observing how large the y-intercept is.

• B. By observing how large the slope of the trend line is.

• C. By observing how closely the points of the scatter plot are located to one another.

• D. By observing whether or not the scatter plot is linear.

4. Which scatter plot best represents the table?

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5. Which of the following books represents an “outlier”?

• A. Book 7

• B. Book 3

• C. Book 8

• D. There were no outliers in the scatter plot.

6. Which is a true statement about the scatterplot ?

• A. As the pages in a book increase, the total number of words decreases.

• B. As the pages in a book decrease, the total number of words decreases.

• C. As the pages in a book increase, the total number of words increases.

• D. Both B and C are true.

7. Which could likely be the variables represented in the scatter plot shown?

• A. The population of a city and the number of houses in the city.

• B. The number of buildings in a city and the number of trees in the city.

• C. The number of cars in a city and the pollution level of the city.

• D. The population of a city and the number of letters in the city’s name.

8. Write an equation for the trend line shown.

• A. y = (-10/3)x - 70

• B. y = (-1/3)x + 70

• C. y = (10/3)x - 70

• D. y = (-10/3)x + 70

9. Write an equation for the trend line shown.

• A. y = -12.5x + 200

• B. y = 12.5x + 250

• C. y = 0.25x + 250

• D. y = -0.25x + 250

A city manager made a scatter plot of the number of retail stores in a certain city over the years. The

scatter plot had a trend line with an equation of y = 11x + 12, where y is the total number of retail

stores and x is the number of years since 1990.

Mark and his family moved to the city in 1997. Use the equation to predict how many retail stores there were in 1997. (answer with a number only)