In 1963 postage was 5 cents per ounce In 1981 postage was 18

In 1963 postage was 5 cents per ounce. In 1981 postage was 18 cents per ounce.

A.Establish a linear model which can be used to estimate the postage per ounce based upon the year (or you use the number of years since 1963).

B. If the trend had continued through today, what would the postage per ounce be?

1963 postage was 5 cents per ounce

Let base year be 1963 ----> (0, 5)

In 1981 postage was 18 cents per ounce.

----> ( 18 , 18)

Now we have two points we can find a linear equation with x as no. of years from 1963

slope = (18 -5)/(18 -0) = 13/18

Y = mx+c

y = 13x/8 +c ----> plug (0,5)

5 = c

A) y = 13x/8 +5

B) Today year 2016 x=53

y = 13*53/8 +5 = 91.13 cents per ounce