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Hello my name is Beth Dixon and this is a video series based on Vicki Borlaug's PowerPoint
presentation on the measures of center mean median mode and midrange
I wish to thank Vicki Borlaug for allowing me to use her power points to create these videos
this is the fifth video in the series on measures of center and we will work another example
example number four
five houses are randomly selected in a certain city and each is appraised the results are listed below
remember my elephant theory how do you eat an elephant
one bite at a time
so let's look at part A first
find the mean value
our numbers are 100,000
$125,000
$150,000
$165,000
and $700,000
remember our formula for the mean
and from what is implied from the wording in our example with the phrase randomly selected
this is a sample so our formula
is x-bar
equals the sum of the X's divided by the number in our sample
if we add up our data we will get
1,240,000
divide that by five
and that gives us $248,000
so the mean value
of the five randomly selected house's is $248,000
next part B
asks us for the median
and the first step is to put the numbers in ascending order which the numbers are already in ascending order
after that we need to find the middle number
which is $150,000 so the median
is $150,000
question C
in this example is the mean or median more representative of the housing values
the median value is more representative because the mean is inflated and 150,000 is a
better description of what the data is doing and gives us
than the $248,000
question D in this example is the mean or median unduly influenced by the extreme value
look how the data appears
when graphed on a number line
notice the location of the mean and the median
the mean is influenced by the extreme value of the one $700,000 house
the median is located closer to most of the data items
so the answer to question D is the mean
here's a quick summary of our results to example four
here's an example for you to try
exercise three is another great one to try as well
exercise four
and lastly exercise five
remember to pause your video and to work the problems and check to see if you have the pdf of these exercises
thank you for watching this series and help with these exercises can be found by contacting me by find e-mail or in person
All spelling errors are mine -- no comments or laughter please. Beth Dixon