A game has 15 balls for each of the letters B, I, N, G, and O. The table shows the results of drawing balls 1,250 times. For which letter is the experimental probability closest to the theoretical probability? Explain

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.