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.
Let X be the national sat score. X follows normal distribution with mean μ =1028, standard deviation σ = 92
The 90th percentile score is nothing but the x value for which area below x is 90%.
To find 90th percentile we will find find z score such that probability below z is 0.9
P(Z <z) = 0.9
Using excel function to find z score corresponding to probability 0.9 is
z = NORM.S.INV(0.9) = 1.28
z =1.28
Now convert z score into x value using the formula
x = z *σ + μ
x = 1.28 * 92 + 1028
x = 1145.76
The 90th percentile score value is 1145.76
The probability that randomly selected score exceeds 1200 is
P(X > 1200)
Z score corresponding to x=1200 is
z = 
z = 
z = 1.8695 ~ 1.87
P(Z > 1.87 ) = 1 - P(Z < 1.87)
Using z-score table to find probability z < 1.87
P(Z < 1.87) = 0.9693
P(Z > 1.87) = 1 - 0.9693
P(Z > 1.87) = 0.0307
The probability that a randomly selected score exceeds 1200 is 0.0307
-.x+7
-x+7=0
-x=-7
x=7...
Not too sure because of the way you wrote the question but this is the interpretation i gave it.
Answer:
8/3, or 2 if you want a whole number
Step-by-step explanation:
Well, the simple answer is 2/(3/4). This is nothing but 2*4/3, which is just 8/3. (I used the theorem that states that dividing is the same as multiplying by the reciprocal)
