98% of dr. williams patients end up with 20-30 vision or better. find the probability that exactly 4 of her next 6 patients end up with 20-30 vision or better.

0.1095

Step-by-step explanation:

Data:

Let:

probability of patients getting well = 0.98

The number of patients. n = 4

The variables are independent, therefore, n = 6

The probability of patients getting 20 - 30 vision, is given by:

P = 4C3 (0.97) (3) (0.03) (1)

  = 0.1095

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.