Statistics homework help!

Question

Use y=2.5x+65 to

(a) find y when x = 8.

(b) find x when y = 75.

Answer 1

y=2.5x+65 to

(a) find y when x = 8.

Since x = 8, we can replace x with the value 8 in the above equation. Therefore,

1. y=2.5(8)+65
2. y = 20+65 = 85

(b) find x when y = 75.

Since y = 75, we can replace y with the value 75 in the above equation. Therefore,

1. 75=2.5x+65
2. 2.5x = 75-65
3. 2.5x = 10
4. x = 10/2.5
5. x = 4

Answer 2

If y = 2.5x + 65 and we let "x" be "8" then:

y = 2.5•8 + 65 [multiply 2.5 and 8 to get 20:

y = 20 + 65

y = 85

If y = 2.5x + 65 and we let "y" be "75" then:

75 = 2.5x + 65 [subtract 65 from both sides of the equation to get:

10 = 2.5x [divide both sides of the equation by 2.5 to get:

10/2.5 = x

x = 4