A members-only speaker series allows people to join for $20 and then pay $1 for every event attended. What is the maximum number of events someone can attend for a total
cost of $50?

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.