Acounterexample is sufficient to prove that a conjecture is false true or false

Find the equation using the point (4,8)

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?

Find the value of x. give reasons to justify your solutions! h ∈ ig