Question

the scatter plot shows the time - spent texting, x, and the time spent exercising, y, by each of 25 students last week. use the equation of the line of best fit, y = - 0.73x + 8.53, to answer the questions below. give exact answers, not rounded approximations. (a) what is the predicted time spent exercising for a student who doesnt spend any time texting? (b) what is the predicted time spent exercising for a student who spends 4 hours texting? (c) for an increase of one hour in the time spent texting, what is the predicted decrease in the time spent exercising? hours hours hours

Explanation:

Step1: Find prediction for no - texting

Substitute $x = 0$ into $y=-0.73x + 8.53$.
$y=-0.73\times0 + 8.53=8.53$ hours.

Step2: Find prediction for 4 - hour texting

Substitute $x = 4$ into $y=-0.73x + 8.53$.
$y=-0.73\times4+8.53=-2.92 + 8.53 = 5.61$ hours.

Step3: Find change per hour of texting

The slope of the line $y=-0.73x + 8.53$ is $- 0.73$. This means for an increase of one hour in the time spent texting, the predicted decrease in the time spent exercising is $0.73$ hours.

Answer:

(a) 8.53 hours
(b) 5.61 hours
(c) 0.73 hours