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
The median is 155
Step-by-step explanation:
You get the numbers from least to greatest then the middle number is your median.
1) factor the denominators: 2b/(b-1)2 - 2/ (b-1)2
2) MAKE SURE YOU HAVE A COMMON DENOMINATOR
3) combine the numerators: 2b-2/(b-1)2
4) distribute 2 from numerator: 2(b-1)/(b-1)2
5) simplify; answer is 2/(b-1)
Answer:
option c
Step-by-step explanation:
option c is right..