The number of people attending graduate school at a university may be modeled by the quadratic regression equation y = 8x2 - 40x+6, where x
represents the year. Based on the regression equation, which year is the best
prediction for when 1206 people will attend graduate school?
A. Year 15
B. Year 18
C. Year 24
D. Year 20

15 years

Step-by-step explanation:

Given the quadratic regression model:

y = 8x² - 40x+6 ; where

y = Number of people attending graduate school ;

x = number of years

The value of x when y = 1206

The equation becomes :

1206 = 8x² - 40x+6

1206 - 6 = 8x² - 40x

1200 = 8x² - 40x

Divide through by 8

150 = x² - 5x

x² - 5x - 150 = 0

x² - 15x + 10x - 150 = 0

x(x - 15) + 10(x - 15)

x - 15 = 0 or x + 10 = 0

x = 15 or x = - 10

Number of years can't be negative,

Hence, x = 15 years

question 1 is 8, question 2 is 9, question 3 is 24

step-by-step explanation:

now, the numbers they give you at the top are the key. from there, you just have to plug and chug! let's try 1, 2, and 3!

key: a=3, b=5, c=6

1. a+5

remember, a=3, so we plug that in to get 3+5=8

2. 15-c

c=6, so we plug that in to get 15-6=9

3. 4b

b=6, so we plug it in to get 4*6=24

time to try the rest on your own! if you put the answers below in a comment, i'll check them for you!