The packaging lists a model airplane’s length as 10.5 in. it also gives the scale as 1: 83. what is the length of the actual airplane to the nearest foot?

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.