On 10-15 i will give brainiest or

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.

Me because i don't understand how to do it.: )

Jimmy can run 3.5 miles in 20 minutes. how far can he run in one hour and ten minutes?