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Sampling Distributions Real Estate
QNT/351 Version 5
University of Phoenix Material
Sampling Distributions – Real Estate Part 2
Directions: Use the real estate data you used for your Week 2 learning team
assignment. Analyze the data and explain your answers.
1.
Review the data and for the purpose of this project please consider the 100 listing prices as a
population.

Explain what your computed population mean and population standard deviation were.
The population mean is an average of a group characteristic. The computed population
mean for the listing prices was $30,661.74. The Standard Deviation is a measure of how
spread out numbers are. In the real estate population, the standard deviation was $9,031.42.
2. Divide the 100 listing prices into 10 samples of n=10 each. Each of your 10 samples will tend to
be random if the first sample includes houses 1 through 10 on your spreadsheet, the second
sample consists of houses 11 through 20, and so on.

Compute the mean of each of the 10 samples and list them:
n=10 (Sample 1: houses 1-10)
n=10 (Sample 2: houses 11-20)
n=10 (Sample 3: houses 21-30)
n=10 (Sample 4: houses 31-40)
n=10 (Sample 5: houses 41-50)
n=10 (Sample 6: houses 51-60)
n=10 (Sample 7: houses 61-70)
n=10 (Sample 8: houses 71-80)
n=10 (Sample 9: houses 81-90)
n=10 (Sample 10: houses 91-100)
Mean=$ 13,050.00
Mean=$ 20,430.00
Mean=$ 24,895.00
Mean=$ 27,335.00
Mean=$ 30,240.00
Mean=$ 33,489.90
Mean=$ 35,250.00
Mean=$ 38,557.50
Mean=$ 40,325.00
Mean=$ 43,045.00
3. Compute the mean of those 10 means.

Explain how the mean of the means is equal, or not, to the population mean of the 100 listing
prices from above.
Population Mean
Mean of Means
$30,661.74
$30,661.74
The reason the means are equal, is contributed to still finding the same average for
equally broke down samples. In our case, we used the average, or middle point, for 10
samples within 10 population samples. By adding these middle point values together and
finding the mean, there was no mathematical change.
4. Compute the standard deviation of those 10 means and compare the standard deviation of the 10
means to the population standard deviation of all 100 listing prices.

Explain why it is significantly higher, or lower, than the population standard deviation.
Copyright © 2016 by University of Phoenix. All rights reserved.
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Sampling Distributions Real Estate
QNT/351 Version 5
Population Std. Dev.
Std. Dev. of 10 Means
$9,031.42
$8,930.17
The computed standard deviation of the 10 means is lower than that of the population of
all 100 listings. This is contributed by the means not having allowed the extreme low and high
values of the complete population to be considered. We only used the averages, or middle
points of 10 sub-samples.
5. Explain how much more or less the standard deviation of sample means was than the population
standard deviation. According to the formula for standard deviation of sample means, it should be
far less.
the formula?
According to the formula
the standard deviation of sample
mean is lower. 101.25 lower. The computed
does agree with the formula
6. According to the Empirical Rule, what percentage of your sample means should be within 1
seem to conform to the rule?
7. According to the Empirical Rule, what percentage of your sample means should be within 2
standard deviations of the population mean? Again, do your sample means seem to conform to
the rule?
8. You used the Empirical Rule because it really gives us more information (and because I asked
you to), but truthfully you should have used Chebyshev’s Theorem. Even though Chebyshev’s
doesn’t tell us much, why should you have used that one instead?
Copyright © 2016 by University of Phoenix. All rights reserved.
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