If the foot length of women follows a normal distribution with a mean of 23 cm, and

81.5% have a foot length between 20 cm and 29 cm, what is your estimate of the standard

deviation of the heights in this population?

divide by 5

step-by-step explanation:

60/5 = 12

x= -3 and

step-by-step explanation:

to find the roots of a cubic, use division or factoring to find the factors then set equal to 0. as this is a difference of cubes, it factors into

where a is the cube root of .

here   this is 27 and the cube root of 27 is 3. so we write using the form:

.

set each factor to 0 and solve for x.

x-3=0

x=3

the quadratic expression does not factor and must be solved using the quadratic formula.

where a = 1, b=3, and c=9

this cubic has two complex roots.

a. she will receive a refund of $278.

step-by-step explanation:

the answer is two. hope this !