Ateacher has a bag of 100 unit cubes. she gives an equal number of cubes to each of the 7 groups in her class. she gives each group as many cubes as she can. how many unit cubes are left over

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.