A consumer advocacy group tested the "on-air" lifetimes of a random sample of 198 cell phone batteries. The mean lifetime was 3.8 hours with a standard deviation of 0.1 hours. The lifetimes are approximately bell-shaped. Estimate the number of batteries with lifetimes between 3.7 hours and 3.9 hours.

sine

step-by-step explanation:

thats not a system of equations, that is a solution

b) k’(6, 4); l’(3, 3)

step-by-step explanation:

a 270° clockwise rotation maps every point (x, y) to (y, -x). (it negates the x-coordinate and then switches it and the y-coordinate.)

this means the endpoints of the side congruent to kl, k' and l', would be mapped as:

k'(-4, 6)→(6, 4)

l'(-3, 3)→(3, 3)