Question

PLEASE HELP I'VE BEEN DOING THIS FOR 2 HOURS!!

The table shows a meteorologist's predicted temperatures for an April day in Washington D.C. Use quadratic regression to find a quadratic model for this data. (Use the 24-hour clock to represent times after noon.)

Time
Predicted Temperature

8 a.m.
50.68

10 a.m.
62.24

12 p.m..
69.75

2 p.m..
73.2

4 p.m...
72.59

6 p.m..
67.93

a.) –0.007x2 + 15.907x – 40.131
b.) –0.507x2 + 14.907x – 36.131
c.) –0.507x2 – 14.907x + 36.131
d.) –1.007x2 + 13.907x – 32.131

Answer 1

–0.507x2 + 14.907x – 36.131

Answer 2

The correct answer is:

b.) –0.507x2 + 14.907x – 36.131

Explanation:

First we enter the data into a graphing calculator. The times are the x-coordinates and the temperatures are the y-coordinates; this is because temperature is dependent upon time.

After we enter this, we run a regression on the calculator. We will run the quadratic regression; the equation is of the form

y = ax²+bx+c.

The values we are given on a Casio fx-9860 gii are:

a = -0.507

b = 14.908

c = -36.136

This is closest to choice B.