A survey of Mr. Thorne’s class shows that 5 out of 8 students will buy lunch today. Based on this result, how many of the 720 students in the school will buy today? Use any strategy to solve.

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.