Answer:
D) 10
Step-by-step explanation:
The slope of the line y=10x+3 is 10 because in the slope form y=mxtb m represents the slope. In this case 10 is m, therefore the slope is 10. This mean the slope rises 10 units and runs 1 unit since slope is also known as rise/run.
We have been given that the standard deviation of a group of 20 scores is 15 and we are asked to find variance.
Since we know variance is square of standard deviation. In order to find out the variance of the given data we have to take the square of 15.

Therefore, our variance is 225.
Write the conjugates of them then FOIL both the top and bottom, then factor
Answer is 20 by plugging the 4 in the equation it equals 20