1 3/4 divided by 2 2/5

Write the expression as a constant , a single trigonometric function, or a power of a trigonometric function. sin x cos x/ tan x

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?

Simplify. (-2)^-3 a. -8 b. -1/8 c. 1/8 d. 8