Question

make a scatter plot of the data below.

x	y
50	178
75	216
100	265
125	323
150	392
175	470.4

using the quadratic regression equation
$y = 0.008x^2 + 0.518x + 131.886$
predict what the y - value will be if the x - value is 200.
a. $y = 83.5$
b. $y = 346.9$
c. $y = 238.1$
d. $y = 555.5$

Explanation:

Step1: Substitute x=200 into the equation

$y = 0.008(200)^2 + 0.518(200) + 131.886$

Step2: Calculate each term

$0.008×40000 = 320$, $0.518×200 = 103.6$, so $y = 320 + 103.6 + 131.886$

Step3: Sum the terms

$320 + 103.6 = 423.6$; $423.6 + 131.886 = 555.486 ≈ 555.5$

Answer:

d. y = 555.5