If 3 varies inversely as x and y=2 when x=25, find x when y=40

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?

If you prove that ∆wxz is congruent to ∆yzx, which general statement best describes what you have proved?

Afamily went out to dinner and their bill was $113.if they want to leave a 19% tip, how much should they leave.