Question

The height, in inches, of each of three boys is 54.0, 48.5, and 46.0, respectively. The height of the fourth boy is denoted by h inches. The average height, A, of the 4 boys can be expressed as a function of h in the form:

A(h) = (c + h)/d

1. What is the domain for the function A(h)?
2. The average height of all 4 boys is 50.5 inches. What is the height of the fourth boy?

Answer 1

53.5

Explanation:

c = the height of the first 3 boys.

c = 54 + 48.5 + 46

c = 148.5

Now you add a fourth boy. His height is h.

A(h)= (c + h)/d

d = the total number of boys which is 4.

The new average is 50.5

A = (c + h)/d

50.5 = (148.5 + h) / 4 Multiply both sides by 4

202 = 148.5 + h Now subtract 148.5 from both sides

202 - 148.5 = h

h = 53.5