Pencils cost $0.20 each. A. Write a function rule to calculate the total cost of any number of pencils.

B. Use your rule to find the total cost of 12 pencils.

How can you tell when x and y are not directly proportional?

Scores on the cognitive scale of the bayley-scales of infant and toddler development range from 1 to 19, with a standard deviation of 3. calculate the margin of error in estimating the true mean cognitive scale score, with 99% confidence, if there are 12 infants and toddlers in a sample.

Use the zero product property to find the solutions to the equation (x+2)(x+3)=12