Scatter Plots Practice

Name: Date:

1. Which graph represents data used in a linear 2. Which scatter diagram shows the strongest positive regression that produces a correlation coefficient correlation? closest to −1 ?

A. A.

B. B.

C. C.

D.

D.

page 1 3. The accompanying table shows the number of new 5. The accompanying table shows the enrollment of a cases reported by the Nassau and Suffolk County preschool from 1980 through 2000. Write a linear Police Crime Stoppers program for the years 2000 regression equation to model the data in the table. through 2002. Year (x) Enrollment (y) x y Year ( ) New Cases ( ) 1980 14 2000 457 1985 20 2001 369 1990 22 2002 353 1995 28 If x = 1 represents the year 2000, and y represents 2000 37 the number of new cases, find the equation of best fit using a power regression, rounding all values to the nearest thousandth.

Using this equation, find the estimated number of new cases, to the nearest whole number, for the year 2007.

6. The accompanying table shows the percent of the adult population that married before age 25 in several different years. Using the year as the independent variable, find the linear regression equation. Round the regression coefficients to the nearest hundredth.

Using the equation found above, estimate the 4. What could be the approximate value of the percent of the adult population in the year 2009 correlation coefficient for the accompanying scatter that will marry before age 25, and round to the plot? nearest tenth of a percent.

Year (x) Percent (y) 1971 42.4 1976 37.4 1980 37.1 1984 34.1 1989 32.1 1993 28.8 1997 25.7 − − A. 0.85 B. 0.16 C. 0.21 D. 0.90 2000 25.5

page 2 Scatter Plots Practice 7. In the physics lab, Thelma determined the kinetic 8. There is a negative correlation between the number energy, KE, of an object at various velocities, V, of hours a student watches television and his or and found the linear correlation coefficient between her social studies test score. Which scatter plot KE and V to be +0.8. Which graph shows this below displays this correlation? relationship?

A. A.

B. B.

C.

C.

D.

D.

page 3 Scatter Plots Practice 9. Which equation most closely represents the line of 10. The number of hours spent on math homework best fit for the scatter plot below? each week and the final exam grades for twelve students in Mr. Dylan’s algebra class are plotted below.

Based on a line of best fit, which exam grade is y x y 2 x A. = B. = 3 + 1 the best prediction for a student who spends about 4 hours on math homework each week? y 3 x y 3 x C. = 2 + 4 D. = 2 + 1 A. 62 B. 72 C. 82 D. 92

page 4 Scatter Plots Practice 11. Which scatter plot shows the relationship between x and y if x represents a student score on a test and y represents the number of incorrect answers a student received on the same test?

A. B.

C. D.

page 5 Scatter Plots Practice 12. The school store did a study comparing the cost 13. Which value of r represents data with a strong of a sweatshirt with the number of sweatshirts positive linear correlation between two variables? sold. The price was changed several times and the numbers of sweatshirts sold were recorded. The . . . . data are shown in the table below. A. 0 89 B. 0 34 C. 1 04 D. 0 01

Cost of $10 $25 $15 $20 $5 Sweatshirt Number Sold 9 6 15 11 14

Which scatter plot best represents the data?

A.

B.

14. Which situation describes a negative correlation?

A. the amount of gas left in a car’s tank and the amount of gas used from it

B. the number of gallons of gas purchased and the amount paid for the gas C. C. the size of a car’s gas tank and the number of gallons it holds

D. the number of miles driven and the amount of gas used

D.

page 6 Scatter Plots Practice Problem-Attic format version 4.4.220 _c 2011–2014 EducAide Software Licensed for use by Zack Holocker Terms of Use at www.problem-attic.com

Scatter Plots Practice 03/19/2015 1. Answer: D 2. Answer: A 3. . Answer: y = 451.431x−0 243 and 272

4. Answer: D 5. Answer: y = 1.08x − 2125

6. Answer: y = −0.58x + 1185.09 and 19.9

7. Answer: B 8. Answer: D 9. Answer: D 10. Answer: B 11. Answer: B 12. Answer: C 13. Answer: A 14. Answer: A