Find the value of this expression if x = 3

Jonah runs 3/5 miles on sunday and 7/10 mile on monday. he uses the model to find that he can ran a total of 1 mile . what mistake does jonah make

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?

The tile along the edge of a triangular community pool needs to be replaced? ?