Problema Solution
In 1960 there were 450000 cases of measles reported in the USA. In 1996, there were 500 cases reported. How many cases of measles would have been reported in 1987 if the number of cases reported from 1960 to 1996 decreased linearly?
Answer provided by our tutors
let
x = the number of years after 1960
y = the number of cases of measles reported
the number of cases reported from 1960 to 1996 decreased linearlymeans:
y = mx + b, where m and b are the constants we need to find
we know that for x = 0, y = 450,000
450,000 = m*0 + b
b = 450,000
for x = 1996 - 1960 = 36 we have y = 500
500 = m*36 + 450,000
by solving for m we find:
m = - 112,375/9
click here to see the step by step solution of the equation:
the equation that describes the number of measle cases is:
y = (- 112,375/9)x + 450,000
for the year of 1987 we have:
x = 1987 - 1960
x = 27 years
y = (- 112,375/9)*27 + 450,000
y = 112,875 cases
click here to see the step by step calculation:
there would have been 112,875 cases of measels reported in 1987.