Question

complete an exponential transformation on the y-value. What is the new y when x = 5?

a)1.301
b) 0.699
c) 1.4472
d) 1.1761

please explain!!!!

Answer 1

x = 0, 1, 2, 3, 4, 5, 6, 7
y = 100, 73, 53, 38, 28, 20, 15, 11

Answer 2

@HawkCrimson

Answer 3

idk because that isn't one of the answer choices

Answer 4

@e.mccormick @chmvijay

Answer 5

You need to fit an exponential curve to the given set of data.
It is called an exponential regression.
For each y value take the log and enter in the table as (x,logy)
Find the regression line or "best fit" line for the data (x,logy).
Find the slope and y-intercept.
Then there is a formula to put it in exponential form and evaluate f(5)

Answer 6

I typed it into my calculator and it gave me a linear transformation model of log y(hat)= -12.1667x + 84.8333

Answer 7

But if you evaluate the above equation for x = 5, you don't get any of the answer choices.

Answer 8

i know that's what i don't understand

Answer 9

Could you just take a log of each y value and post it in a table as (x,logy)?

For example, x log(y)
0 log(100) = 2
1 ?
2 ?

Answer 10

it wont let me

Answer 11

x 0, 1, 2, 3, 4, 5, 6, 7
y 100, 73, 53, 38, 28, 20, 15, 11
log(y) 2,

complete the rest of the table. All you have to do is find log of each value and enter it in the table.

Answer 12

log(73) = ?
log(53) = ?

The one we really need is log(20) = ?

Answer 13

log(20) = 1.301

Answer 14

It looks like that is all they are looking for in this problem based on the answer choices. So you don't have to do the next step of finding the actual exponential regression curve.