# A Line has only 1 Slope

A line is very simple in that it has the same slope everywhere. So, to find out how much a PC tech makes per hour, you just need to measure how much we made in any single hour – such as the first one:

If you want to get fancy, you can pick a different hour, but to me it seems like more work for the same answer. For example, you could say, between hours 1 and 2, the PC Tech earned $42 - $21 = $21 extra dollars:

I mention this only because when people want to demonstrate finding a slope, they often draw a figure that looks like this;

But you now know that, **assuming that the line goes through (0,0)** , its much **easier to find the slope
by just finding the value of y at x=1**. If it's not possible to distinguish the value of y at x=1, then you may need to use a larger number:

### What is the pay rate for the forest conservation worker? How about the veterinarian?

(All wage data taken from Monster.com)

(To make this problem interactive, turn on javascript!)

- I need a hint ... : It's not really possible to see (the value of the paycheck)at x = 1 hour. So pick a bigger x value, like x = 10 hrs.

- ...another hint ... : If the forester works 10 hours, she makes 220 dollars...

- ...another hint ... : 220 dollars / 10 hours = ? dollars / 1 hour

- ...another hint ... : Now do the same for the vet...

#### I think I have the answer:

Forester = $22/hr,

Veterinarian = $42/hr

The equation for a straight line is

"Y-intercept" is just a fancy word for "where the line crosses the y axis". We know that the lines we're talking about go through (0,0) -- there, the y-intercept must be zero, so the equation is simply y = mx.

Copyright University of Maryland, 2007

You may link to this site for educational purposes.

Please do not copy without permission

requests/questions/feedback email: mathbench@umd.edu