Can anyone answer this question for me.

Abcd is a square. what is the measure of angle bac

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.

Eden has a part time job. she is paid ? 7.20 an hour the week she worked 18 and a half hours how much is she paid