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© 2014 Pacific Crest
297
Step
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6.
Validate
According to the CDC, the average height for all US women is 63.8 inches.
It appears that the clients for the fashion designer are not a random sample of
the entire population. In order to validate this study a second sample of clients
should be examined.
Scenario 2:
Skewed Data
A person wants to purchase a single-family home in an established community.
She is interested in the selling prices of recently sold homes in that community.
She wants to know what the “typical” price is for such a home. She researches
the list prices on zillow.com.
Step
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1.
Describe the data
set
The following is a set of list prices for homes in an affluent neighborhood.
$709,000 $1,500,000 $1,199,993 $1,299,000 $1,595,000
$585,000
$615,000 $1,650,000
$555,000
$495,000
$1,199,000
$549,000
$499,999 $1,275,000
$420,000
$199,900
$449,000
$720,000 $1,199,000
$264,993
$1,549,993
$624,993
$585,000
$289,000
$395,000
2.
Describe the type
of data
Selling prices are ratio level of measurement. The differences are relevant and
$0 is a meaningful measure.
3.
Construct a
histogram or bar
graph
0
1
2
3
4
5
6
7
8
500
1000
1500
2000
Use technology to construct
a histogram. Determine if
the data has outliers or if it
is skewed.
There are no outliers. The
data does not seem to be
symmetric.
4.
Determine which
measures of CT
are reasonable
Since the data is ratio interval of measurement, the mean, median and mode
are reasonable.
The data set seems skewed positively so the median may be the best measure
of central tendency.
7.1 Central Tendency