1) The chart shows the cost of a used car -- of a specific model and year -- at different total mileages. Using a graphing calculator, find the equation for the line of regression, the Pearson product-moment correlation value (r), and the predicted mileage for a used car when it costs $3000.
A) y = -0.017x + 325; r = -0.98; 274,000 miles
B) y = -0.010x + 160; r = -0.88; 130,000 miles
C)y = -0.037x + 375; r = -0.78; 264,000 miles
2) The chart shows the average monthly sales in thousands of dollars for eight sales representatives and the years of sales experience for each representative. Using a graphing calculator, find the equation for the line of regression, the Pearson product-moment correlation value (r), and the predicted years of experience required to reach $40,000 in sales.
A)y = 0.38x + 3.1; r = 0.83; 18 years
B)y = 0.33x + 1.6; r = 0.79; 15 years
C)y = 0.28x + 1.6; r = 0.79; 13 years
D)y = 0.33x + 3.6; r = 0.89; 17 years
3)
Rocky Ridge Observatory has records of comet sightings over a 10-year period. Which model relates the number of comets sighted as a function of the number of years since 2000? Using the model, what year might comet sightings exceed 150?
A)f(x) = 4.85x + 69.85
during the year 2017
B)f(x) = 4.58x - 337
during the year 2015
C) f(x) = 4.85x + 21
during the year 2016
D)f(x) = 4.95x - 376
during the year 2016
