Vertex of the graph of f(x) = x 2 + 2x - 15

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?

Acircle has a circumference of 7.850 units. what is its radius?

Harry the hook has 7 1/3 pounds of cookie dough.she uses 3/5 of it to bake cookie. how much cookie dough does she use to make cookie?