Plz help me with this question

If x = 12 and y = 3, what is the value of x - y 2? 81 6 3 18

If the cost to mail a package is an initial $5 and $0.28 for every pound the total cost to mail a package was $11.27, how much did the package weigh?

The birth weights of newborn babies in the unites states follow in a normal distrubution with a mean of 3.4 kg and standard deviation of 0.6 kg. reaserches interested in studying how. children gain weights decide to take random samples of 100 newborn babies and calculate the sample mean birth weights for each sample