SOLUTION: Hi, I'm having problems solving this problem. I need to write an equation in either slope-intercept form, or the standard(general)form: The proper crutch length for someone who

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Hi, I'm having problems solving this problem. I need to write an equation in either slope-intercept form, or the standard(general)form: The proper crutch length for someone who       Log On


   

Question 155851: Hi, I'm having problems solving this problem. I need to write an equation in either slope-intercept form, or the standard(general)form:
The proper crutch length for someone who has sustained a leg injury and is x inches tall, is given by: y=0.72x+2 (where y is in inches)
a) What is the proper crutch length for someone who is 6 feet tall?
My answer was: y=0.72(6) + 2
= 4.32 + 2
Y= 6.32 if that the correct answer.
Can you help me solve b,c,& d.
b) If someone donates a crutch, which is 40 inches long, to a physical therapy clinic, what should be the height of the patient that the clinic who should receive it?
c) By how much does the length of the crutch increase or decrease for every increase of 1 inch in height of the patient?
d) Graph the equation for x ranging from 30 inches to 100 inches. Choose a suitable scale.
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Watch your units.
It'd be tough for a 6 foot patient to use a 6 inch crutch.
You need to convert the height from feet to inches to use the formula.
6 feet=72 inches
y=0.72x%2B2
Let's change the equation to make it more meaningful
CH=0.72%28PH%29%2B2
where CH stands for crutch height (in inches) and PH, patient height (in inches).
a) PH=72
CH=0.72%28PH%29%2B2
CH=0.72%2872%29%2B2
CH=53.84
b)CH=40
CH=0.72%28PH%29%2B2
40=0.72%28PH%29%2B2
0.72%28PH%29=38
PH=52.78
c) For every inch of PH, CH changes by 0.72.
d) CH=0.72%28PH%29%2B2
At 30 inches,
CH=0.72%2830%29%2B2
CH=23.6
At 100 inches,
CH=0.72%28100%29%2B2
CH=74