Emily is entering a bicycle race for charity or mother pledges $0.90 for every 0.5 Miles She bikes if Emily bikes 16 miles how much will her mother donate

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.