A student at a junior college conducted a survey of 20 rando

A student at a junior college conducted a survey of 20 randomly selected full-time students to determine the relation between the number of hours of video game playing each week, x, and grade-point average, y. She found that a linear relation exists between the two variables. The least-squares regression line that describes this relation is ^y= -0.05571x+2.9199. (a) predict the grade-point average of a student who plays video games 8 hours per week. (b) for each additional hour that a student spends playing video games in a week the grade point average will_ by _ points, on average. (c) what is the grade point average for students who play 7 hours a week?

Solution

a)

As

y^ = -0.05571x+2.9199

Then if x = 8,

y^ = -0.05571*8 + 2.9199

y^ = 2.47422 [ANSWER]

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b)

Using the definition of slope,

for each additional hour that a student spends playing video games in a week the grade point average will [DECREASE] by [0.05571] points, on average.

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c)

As

y^ = -0.05571x+2.9199

Then if x = 7,

y^ = -0.05571*7 + 2.9199

y^ = 2.52993 [ANSWER]