This is physical science questions, can someone with 7-9

2people are trying different phones to see which one has the better talk time. chatlong has an average of 18 hours with a standard deviation of 2 hours and talk-a-lot has an average of 20 hours with a standard deviation of 3. the two people who tested their phones both got 20 hours of use on their phones. for the z-scores i got 1 for the chatlong company and 0 for talk-a-lot. what is the percentile for each z-score?

Write as a product: ac^2–ad+c^3–cd–bc^2+bd

Which shows a reasonable estimation for 124% of 42 using the distributive property?