What is the missing number in the sequence? 9/16, 9/8, 9/4, 9/2, 9

What is the solution to the inequality

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?

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?