if i select three uniformly at random, what is the probability that exactly one of them is wearing a watch

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 of the following is the explicit rule for a geometric sequence defined a recursive formula of a -5a for which the first term is 23?

What is the effect on the graph of the function f(x)=x when f(x) is replaced with -f(x)+4