We are given Zak's laps jogged along with the minutes elapsed.
If the equation of a line is:
m = kx + b
Where m is the number of minutes.
k is the slope of the line
x is the Laps
b is the y-intercept (or where the line crosses the y-axis)
In order to get the equation of the relationship between Laps (x) and Minutes (m),
we need to calculate the slope k and intercept b.
The formulas for doing these are given below:
[tex]\begin{gathered} m=\frac{\sum(x_i-X)(y_i-Y)}{(x_i-X)^2} \\ \text{where,} \\ x_i=\text{data points of Laps x} \\ X=\text{ Average of the Laps x} \\ y_i=\text{data points of Minutes m} \\ Y=\text{Average of Minutes m} \end{gathered}[/tex]
The formula for intercept (b) is;
[tex]b=Y-kX[/tex]
where Y and X are the averages of m and x values from the table.
[tex]\begin{gathered} Y=\frac{\sum m}{n}\text{ (n is the number of data values of Y)} \\ Y=\frac{17+41+65}{3} \\ \\ Y=41 \\ \\ X=\frac{\sum x}{n}\text{ (n is the number of data values of X)} \\ X=\frac{1+3+5}{3} \\ \\ X=3 \end{gathered}[/tex]
In order to be tidy and quick, a table is used to solve.
This table is shown in the image below:
Therefore, we can now calculate slope (m):
[tex]\begin{gathered} m=\frac{\sum(x_i-X)(y_i-Y)}{(x_i-X)^2} \\ \\ m=\frac{\mleft(-24\mright)\mleft(-2\mright)+0\mleft(0\mright)+\mleft(24\mright)\mleft(2\mright)}{4+0+4} \\ m=\frac{96}{8} \\ \\ m=12 \end{gathered}[/tex]
Now that we have slope (k) = 12, we can get the intercept b
[tex]\begin{gathered} b=Y-kX \\ Y=41-12(3) \\ Y=41-36 \\ Y=5 \end{gathered}[/tex]
Therefore, the equation is:
m = 12x + 5
