Which lines best approximate the directrices of the ellipse? Round to the nearest tenth. x = −4.6 and x = 4.6 x = −3.5 and x = 3.5 y = −4.6 and y = 4.6 y = −3.5 and y = 3.5

Find the value of the cosine for angle a

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.

Ineed the solution to this problem and the steps.