My 7th-grade math is so har for me plz me? just the answer or the explianation if u want idc just !

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?

Which is greater, 7 p 5 or 7 c 5? 7p5 7c5

Which expression is rational? 6. , square root two, square root 14, square root 49