Question

the number of hours that 20 people spent watching television per day, in relation to age, is graphed. this quadratic equation represents the model for the set of data.
$y = 0.004x^2 - 0.314x + 7.5$
based on the model, approximately how much time does an 18 - year - old spend watching television each day?
a. 0.5 hour
b. 3 hours
c. 7.5 hours
d. 2 hours

Explanation:

Step1: Substitute $x=18$ into equation

$y = 0.004(18)^2 - 0.314(18) + 7.5$

Step2: Calculate squared term

$18^2 = 324$, so $0.004\times324 = 1.296$

Step3: Calculate linear term

$0.314\times18 = 5.652$

Step4: Compute final value

$y = 1.296 - 5.652 + 7.5$

Answer:

B. 3 hours