Can anyone help me out on this problem please?.

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.

Tan198=asin164=? how to solve this? ?

Assume that y varies inversely with x. if y=1.6 when x=0.5 find x when y=3.2 acellus answer