You measure 33 textbooks' weights, and find they have a mean weight of 37 ounces. Assume the population standard deviation is 8.2 ounces. Based on this, construct a 95% confidence interval for the true population mean textbook weight.

34.2022 < X < 39.7978

Step-by-step explanation:

For a 95% confidence interval, Z = 1.960

Sample size (n) = 33

Mean weight (X) = 37 ounces

Standard deviation (s) = 8.2 ounces

The relationship that describes a 95% confidence interval is:

Applying the given data, the Lower (L) and Upper (U) limits are:

The 95% confidence interval is:

34.2022 < X < 39.7978

step-by-step explanation:

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.