A series of statistical questions was asked to dog owners. What are the variables for this study? Check all that apply.

Need to increase the numbers of customers i talk to daily by 20% how many customers do i need to talk to if i talk to a average of 8 customers per hour during an 8 hour shift

Which of the following expressions is equal to 2x^2+8

Is the square root of 4 plus the square root of 16 rational?