Answer:
The standard deviation of that data set is 3.8
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 55
95% of the data fall between 47.4 and 62.6. This means that 47.4 is 2 standard deviations below the mean and 62.6 is two standard deviations above the mean.
Using one of these points.
55 + 2sd = 62.6
2sd = 7.6
sd = 7.6/2
sd = 3.8
The standard deviation of that data set is 3.8
A cylinder with a circumference of about 50 units is formed.
Step-by-step explanation:
Step 1:
The perimeter of the square is 32 units. The perimeter of a square is given by 4 times its side length.

So the side length of the square is 8 units.
If a square is rotated a cylinder will be formed. So the options with a cone are wrong as a cone is formed when a triangle is rotated.
Step 2:
To calculate the circumference of the cylinder, we multiply 2π with the radius. The radius is the same as the side length of the square. So r is 8 units.
The circumference of the cylinder 
So the circumference of the cylinder is approximately equal to 50 units so the answer is the fourth option, a cylinder with a circumference of about 50 units.
To solve this problem you must apply the proccedure shown below:
1- You must apply the following formula:

Where
is the residual,
is the observed value
and
is the predicted value
.
2- You only need to substitute the
into the equation
and then, you must apply the formula for calculate the residual:


The answer is: The residual is 
Answer:
Step-by-step explanation:
x, height of men is N(69, 2.8)
Sample size n =150
Hence sample std dev = 
Hence Z score = 
A) Prob that a random man from 150 can fit without bending
= P(X<78) = P(Z<3.214)=1.0000
B) n =75
Sample std dev = 
P(X bar <72) = P(Z<9.28) = 1.00
C) Prob of B is more relevent because average male passengers would be more relevant than a single person
(D) The probability from part (b) is more relevant because it shows the proportion of flights where the mean height of the male passengers will be less than the door height.
Answer:
26.11% of women in the United States will wear a size 6 or smaller
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

In the United States, a woman's shoe size of 6 fits feet that are 22.4 centimeters long. What percentage of women in the United States will wear a size 6 or smaller?
This is the pvalue of Z when X = 22.4. So



has a pvalue of 0.2611
26.11% of women in the United States will wear a size 6 or smaller