a sample of 58 items is selected. The mean of the sample is determined to be 36. The associated number of degrees of freedom for reading the t value is:

This question is incomplete, the complete question is;

In order to determine an interval for the mean of a population with unknown standard deviation, a sample of 58 items is selected. The mean of the sample is determined to be 36. The associated number of degrees of freedom for reading the t value is :

a. 35.

b. 57.

c. 36.

d. 58.

Option b. 57 is the correct answer.

Step-by-step explanation:

Given that;

sample size n = 58

sample mean x" = 36

degrees of freedom for reading the t value is = ?

we know that;

Degree of freedom df = n - 1

where n is the sample size

so we substitute

Degree of freedom df = 58 - 1

Degree of freedom df = 57

Therefore Option b. 57 is the correct answer.

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.

step-by-step explanation:

i'm pretty sure it would take 20 hours because it's half the men so you multiply the number of hours it takes by 2