Answer:
Step-by-step explanation:
The first one
Answer: C) 50%
Step-by-step explanation:
If the polarizes are parallel, then it will be 0%. But if they're both perpendicular than it will be 50%. If they are neither parallel nor perpendicular, than it will be less than 50% and greater than 0%
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.