Answer:
The z score for bolt of diameter 18.12 mm is 1.20.
Step-by-step explanation:
Let <em>X</em> = diameter of bolts.
It is provided that the random variable <em>X</em> follows a Normal distribution with mean, <em>μ</em> = 18 mm and standard deviation, <em>σ</em> = 0.10 mm.
A <em>z</em>-score is a standardized score, a numerical, that defines how far a data value from the mean.
The distribution of <em>z</em>-scores is defined by the Standard Normal distribution.

The formula to compute the <em>z</em>-score is:

The value of the diameter of a bolt is, <em>x</em> = 18.12 mm.
Compute the <em>z</em>-score for this value as follows:

Thus, the z score for bolt of diameter 18.12 mm is 1.20.
Answer:
I am not so clear about this question
Answer:

Step-by-step explanation:
The formula of a surface area of a cube:

The formula of a volume of a cube:

We have

Calculate the edge length (<em>a</em>).
<em>divide both sides by 6</em>

Calculate the volume of a cube:

Answer:
He can go 10.78 miles
Step-by-step explanation:
This problem can be solve by creating a proportion, knowing that 15.4 miles is to one gallon the same as "x" miles (our unknown) is to 0.7 gallons. This can be set in math terms as the equation that relates these two ratios of miles per gallon:

and to solve for the unknown number of mile, we multiply both sides of the equation by "0.7 gallon" in order to isolate our unknown:
