Monday

July 28, 2014

July 28, 2014

Posted by **guitarman** on Monday, March 29, 2010 at 12:22pm.

When I saw the word LINEAR, I immediately thought about y = mx + b.

Find an equation that gives the maximum healthy weight y for a person whose height is x inches over 4 feet, 10 inches.

HINTS GIVEN IN MATH BOOK:

x = 0 represents a person 4 feet, 10 inches

x = 2 represents a person 5 feet tall, etc.

The correct equation is y = 5x + 115. I was able to find the slope 5 and got as far as y = 5x. My question is: where did 115 come from?

I look forward to your insight and guidance.

Thanks

- math -
**Reiny**, Monday, March 29, 2010 at 1:01pm5 ft, 5 inches = 5.4166667 feet

6 ft, 3 inches = 6.25 feet

so I look at the given data as 2 ordered pairs,

(5.4166667 , 150) and (6.25 , 200)

slope = (200-150)/(6.25-5.4166667) = 60

so y = 60x + b

using the point (6.25,200)

so a person 4 ft 10 inches tall or 4.8333333 ft should weigh

y = 4.8333333(60) - 175 = 115 lbs

I really do not understand their hint.

200 = 60(6.25) + b

b = -175

so my equation is

y = 60x - 175 , where x is feet and y is lbs.

checking the other point

if x = 5.4166667

y = 60(5.4166667) - 175 = 150

my equation works for both data values.

- math -
**guitarman**, Monday, March 29, 2010 at 1:19pmThank you. I also played with this question some more and learned that

y = 5x - 175 works just the same. You said the slope is 60 but 60 inches divided by 12 inches = 5 feet. I decided to use 5 for the slope.

Both equations work very well.

**Related Questions**

Applied Calculus - For the average person that is still growing, the rate of ...

Business math - PROBLEM 1 The video discusses the requirements of a package to ...

mathhhhh - For a person of height h (in inches), a healthy weight W (in pounds) ...

algebra - To balance a seesaw, the distance, in feet, a person is from the ...

math - Can you tell me if I have the correct answer to this problem. A formula ...

math - Todds weight dropped from 220 pounds to 190 pounds. Cassidys weight ...

Math - You have 200 feet of fencing to enclose a rectangular plot that borders ...

math - This is confusing: This proportion can be changed to (0.45)y = x, where x...

algebra - You may have to convert from feet to miles several times in this ...

Math help - A catapult launches a boulder with an upwark velocity pf 184 feet ...