An individual wanted to determine the relation that might existbetween speed and miles per gallon of an automobile. Let X be theaverage speed of a car on the highway measured in miles per hourand let Y represent the miles per gallon of the automobile. Thefollowing data is collected:
X
50
55
55
60
60
62
65
65
Y
28
26
25
22
20
20
17
15
  •  In the space below, use technology toconstruct a scatterplot of the bivariate data set.




  •  What is the value for r? Interpret thisvalue, would you say that the correlation is positive or negative?Strong or Weak? How do you know?


  •  From the regression equation givenabove, what value is the slope of the line? Interpret this slope,what does it tell us about the relationship between average speedand miles per gallon?
  •  Predict the miles per gallon of a cartraveling 63 miles per hour.
  •  Predict the average speed of a carwhose fuel mileage is 23 miles per gallon.

(f) Find r squared. What does this statistic tell us about betweenaverage speed and miles per gallon?

