Question 124303
The number N, in millions, of hearing impaired individuals of age x can be approximated by:
:
 N = -0.00006x^3 + 0.006x^2 - 0.1x + 1.3
:
Approximate to the nearest million the number of hearing impaired individuals of ages 50 - 60.
N = ____ million individuals of age 50.
:
 N = -0.00006x^3 + 0.006x^2 - 0.1x + 1.3
:
Substitute 50 for x in the above equation:
 N = -0.00006(50^3) + 0.006(50^2) - 0.1(50) + 1.3
 N = -7.5 + 15 - 5 + 1.3
 N = 3.8 million age 50
:
:
N = ____ million individuals of age 60.
:
Substitute 60 for x in the above equation:
 N = -0.00006(60^3) + 0.006(60^2) - 0.1(60) + 1.3
 N = -12.96 + 21.6 - 6 + 1.3
 N = 3.94 million age 60
:
Now do they mean total number of deaf people at all ages from 50 to 60?
:
Using the average of of the two ages and multiplying that by 10 it would be:
{{{((3.8+3.94))/2}}} * 10 = 38.7 million ages 50 to 60