The table shows the cost of hats.

What is the unit rate for the costs of hats?
A. $7.50 per hat
B. $15.00 per hat
C. $22.50 per hat
D. $30.00 per hat

Is the following relation a function? x y 1 4 −1 −2 3 10 5 16 yes no

Determine the mean and variance of the random variable with the following probability mass function. f(x)=( 729divided by 91) (1 divided by 9) superscript x baseline comma x equals 1,2,3 round your answers to three decimal places (e.g. 98.765).

What is the distance between a and b? round your answer to the nearest tenth. a coordinate plane is shown. point a is located at negative 1, 5, and point b is located at 4, 1. a line segment connects the two points.