Find the regression​ equation

Question

Find the regression​ equation, letting the first variable be the predictor​ (x) variable. Using the listed​ lemon/crash data, where lemon imports are in metric tons and the fatality rates are per​ 100,000 people, find the best predicted crash fatality rate for a year in which there are

525 metric tons of lemon imports. Is the prediction​ worthwhile?

Lemon Imports	227	266	361	466	540
Crash Fatality Rate	16.1	15.9	15.7	15.5	15.2

Answer 1

y=-.002621x + 16.65

15.273975= -.002621(525)+16.25

y = about 15.3

you could have guessed that from the table as 525 is a little less than 540

so y is a little more than 15.2 which is about 15.3

525 is 59/74 of the way from 466 to 540

so 15.3 is about 59/74 of the way from 15.5 to 15.2

or closer to 15.3 than to 15.4

it's an inverse relationship, as x goes up, y goes down

y=ax+b

is the regression line equation

where b= the average of y values= 16.65

a = (sum of xy - (sumx)sumy)/n)/(sum(x^2)-(sumx)^2/n) = about -.002621