Question

payton collected data to show the relationship between the number of hours he practices and the number of errors he makes when playing a new piece of music. the table shows his data.
practice makes better

number of hours	1	2	3	4	5	6	7	8
number of errors	36	34	30	31	23	16	11	5

which is the approximate slope of the line of best fit for the data?
-5.5
-4.5
-2.0
-1.0

Explanation:

Step1: Recall slope formula

The formula for the slope $m$ of the line of best - fit using two points $(x_1,y_1)$ and $(x_2,y_2)$ is $m=\frac{y_2 - y_1}{x_2 - x_1}$. We can use the first and the last points from the data. Let $(x_1,y_1)=(1,36)$ and $(x_2,y_2)=(8,5)$.

Step2: Substitute values into formula

$m=\frac{5 - 36}{8 - 1}=\frac{- 31}{7}\approx - 4.43\approx - 4.5$.

Answer:

-4.5