Jason has $90 to spend. he wants to purchase a bag for $30, one eraser for $10, and three pencils. each pencil cost the same price. this will use up all of jason's money. determine the price of a pencil.

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.