The waiting times for the treatment of a specialized steel are assumed to be normally distributed, with unknown mean and standard deviation. As an enterprising co-op student, you perform 25 tests. Find an interval bracketing the probability that you will observe a standard deviation in waiting time exceeding 5 minutes when the true standard deviation is (a) 4.3 minutes or (b) 6.0 minutes.

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.

c > -10.55

step-by-step explanation:

b

step-by-step explanation:

i dont know

kayla would of sent 8

step-by-step explanation: