Answer:
21. is 18 dollars
22. is 75 dollars
Step-by-step explanation:
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.
Round
321.786 is about 322
240.23 is about 240
322+240=562
about 562
Please, enclose those binomials x+4 and y+7 inside parentheses:
(x+4) / 4 = (y+7) / 7. Find (x/4).
Let's solve the above equation for x:
x+4 = 4(y+7)/7. Then x = 4(y+7) / 7 - 4
Last, divide all 3 terms by 4: x/4 = (y+7) / 7 - 1 (answer)
y + 7 - 7
You could also type this as x/4 = ------------- = y/7
7