Britney sells mattresses at a furniture store. she makes a 9.75% commission on each mattress she sells. last week, britney sold four mattresses. the sale price of each mattress is shown in the table.

mattress 1 $2400
mattress 2 $3200
mattress 3 $1900
mattress 4 $800

step-by-step explanation:

you can add the two numbers and divide the result by 2. or you can find the gap between the two numbers and add half of this to the smaller number.

answer: .64

step-by-step explanation

set up the formula for standard deviation for this set of numbers, then simplify