Please answer Dana has already baked 4 pies, and she can bake 2 pies with each additional cup of sugar she buys. How many additional cups of sugar does Dana need in order to bake a total of 42 pies?

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?