A new sports conference consisting of ten teams is forming. if each team plays every other team in the conference , how many games does the conference have to schedule each year ?

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.