Answer:
a) 2.0702
b) 2.07
Step-by-step explanation:
Given:
Sample, n = 840
standard deviation, σ = 60
a) The standard deviation of the sampling distribution, will be:
= 2.0702
Standard deviation of the sampling distribution is 2.0702
b) According to the 68 part of the 68-95-99.7 rule, 68% of all values of x fall within 1 standard deviation on either side of the unknown mean μ.
Therefore, missing number will be:
= 1 * 2.0702
= 2.0702 ≈ 2.07
Answer: (27, 9)
Multiply the original coordinates by the scale factor 3 to get this answer
9*3 = 27
3*3 = 9
This only works if the center of dilation is the origin.
The general rule is where k is the scale factor.
Answer:
This value means that his shoe size is 2.9 deviations above the population mean.
And we can find the approximate percentile for his measure like this:
This correspond to the 99.8 percentile, so then his shoe size is 99.8% above all the shoe sizes.
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the shoe size of a population, and for this case we know the distribution for X is given by:
Where represent the mean and
the population standard deviation.
For this case we know that a man obtain a z score of z=2.9
This value means that his shoe size is 2.9 deviations above the population mean.
And we can find the approximate percentile for his measure like this:
This correspond to the 99.8 percentile, so then his shoe size is 99.8% above all the shoe sizes.