he following times were recorded by the quarter-mile and mile runners of a university track team (times are in minutes). Quarter-Mile Times: 0.91 0.96 1.05 0.94 1.02 Mile Times: 4.53 4.35 4.61 4.71 4.51 After viewing this sample of running times, one of the coaches commented that the quarter-milers turned in the more consistent times. Use the standard deviation and the coefficient of variation to summarize the variability in the data. Quarter-milers Standard deviation (to decimals) Coefficient of variation (to decimal) % Milers Standard deviation (to decimals) Coefficient of variation (to decimal) % Does the use of the coefficient of variation indicate that the coach's statement should be qualified

757764

step-by-step explanation:

de77737dd

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240

my guess would be b and d, but i didn’t actually get out the pen and paper. lol