Please consider the complete question.
Michelle bought the same fabric on 3 different occasions and recorded the data below.
Yards of Fabric Total Cost
2.2 $2.53
3.6 $4.14
4.2 $4.83
What was the price per yard of fabric?
To find the cost per yard of fabric, we will divide cost of yards by number of yards.
Let us find cost per yard using 2nd set of data.
Similarly we will find cost per yard for 3rd set of data.
Therefore, the cost per yard of fabric is $1.15.
To write an equation for this line, you first need to understand how to derive it.
Let's utilize slope-intercept form, as it's the easiest to understand compared to any other form for line functions:
y = mx + b
m: The slope of the line
b: The y-intercept (The point where the line is at the y-axis)
Now that we've defined our variables, how do we go about making the actual equation? Let's start off with the slope, m.
The slope is a measure of how high or low the line is. The number is a ratio between the rise and run of a slope. In other words, it is essentially
Let's look back at the graph. In the time interval from 1 to 2 seconds, we see that the line rises by 22 feet. Because the time interval is only 1 second, the run is 1 second.
Therefore:
m =
m =
m = 22
We now have the first variable of the equation.
y = 22x + b
What about b? As we established earlier, b is the value of coordinate y at the y-intercept. Essentially, to find b we need to know what the value of y is when the coordinate x is 0.
As you can see from the graph you made, the value of y when x is 0 is also 0. This makes sense, too. How can the cheetah travel distance at 0 seconds when it obviously hasn't started moving? We now know b = 0. Now, we have gotten all of the variables we need to make a full equation:
y = 22x + 0
y = 22x
If you'd like me to explain how I did anything, just ask!
- breezyツ