Question
MATH399 Applied Managerial Statistics
Week 1 Assignment Using Measures of Central Tendency
Question
Given the following frequency table of values, is the mean or
the median likely to be a better measure of the center of the data
set?
Value323334353637Frequency236221
QuestionGiven the following list of values, is the mean or
the median likely to be a better measure of the center of the data
set?
25, 29, 23, 26, 25, 27, 10, 26, 23, 23, 26
QuestionGiven the following list of values, is the mean or
the median likely to be a better measure of the center of the data
set?
26, 27, 26, 30, 27, 31, 29, 28, 53, 29
Determining the Best Measure of Center
Key Terms
•
Mean: the sum of all the items in a list divided by the number of
items in the list
The term Mean is often used interchangeably with the term
Average
•
Median: a number that splits a data set in half, with one half
smaller and one half larger; the center or middle value of a data
set
•
Mode: the number(s) that occurs most often in a data set
•
Outliers: values that are very different from the rest of the
values in a data set
QuestionGiven the following frequency table of values, is the
mean or the median likely to be a better measure of the center of
the data set?
Value252627282930Frequency223362
QuestionGiven the following frequency table of values, is the
mean or the median likely to be a better measure of the center of
the data set?
Value27282930313233343536373839404142434445Frequency1000000000001215223
QuestionGiven the following list of values, is the mean or
the median likely to be a better measure of the center of the data
set?
35, 39, 37, 37, 38, 34, 35, 37, 65
QuestionGiven the following list of values, is the mean or
the median likely to be a better measure of the center of the data
set?
29, 30, 31, 30, 30, 34, 32, 28
Determining the Best Measure of Center
With three different measures of central tendency—mean,
median, and mode—it is sometimes difficult to decide which is the
best option to summarize your data. Let’s look at each measure and
discuss when we should use it.
Mode
The mode is most often used with nominal (categorical) and
ordinal data, when it is not meaningful to take the mean or the
median. For example, to summarize a survey of voters’ preferred
candidate, it would make sense to summarize the data by saying
which candidate was most preferred. That would be the mode in this
case (the value which occurs the most often).
Similarly, to summarize customer satisfaction on a survey,
where the choices might be “Very Dissatisfied”, “Dissatisfied”,
“Satisfied”, or “Very Satisfied” it would be reasonable to identify
the category which most customers chose, rather than trying to use
the mean or median.
Mean and Median
The mean is useful in data sets that do not have any
outliers, which are values that are very different from the rest of
the values. The reason that outliers are bad for the mean is that a
few very large (or very small) values can pull the mean up or down,
which in many cases distorts or misrepresents the data.
If a data set has outliers, then it is typically better to
use the median, since it will not be distorted by a few very large
or very small values.
The histogram below shows the frequencies of a data set. As
you can see, there are many small values with high frequencies, and
a few outliers which are much larger. The mean and the median are
also labeled with dotted lines. As you can see, the mean has been
pulled up by the large outliers, whereas the median gives a better
idea of the middle of the data.
A coordinate plane has a horizontal axis titled Value
labeled from 0 to 16 in increments of 2 and a vertical axis titled
Frequency labeled from 0 to 8 in increments of 2. Bars are plotted
on the graph where the horizontal coordinate value is listed first
and the vertical coordinate value is listed second: 1,7; 2, 8; 3,
6; 4, 2; 5, 2; 6, 1; 10, 1; 11, 1; 15, 1. A vertical dashed line at
2 on the Value axis is labeled Median. A vertical dashed line at
approximately 3.5 on the Value axis is labeled Mean.
Key Terms
•
Mean: the sum of all the items in a list divided by the number of
items in the list
The term Mean is often used interchangeably with the term
Average
•
Median: a number that splits a data set in half, with one half
smaller and one half larger; the center or middle value of a data
set
•
Mode: the number(s) that occurs most often in a data set
•
Outliers: values that are very different from the rest of the
values in a data set
In the real world, household income often has a distribution
like the above one, where most household incomes are low or
moderate, but there are also a few very large values. In such
situations, the median income is often a better representative of
the typical household than the mean.
Example
QuestionWould the mean or the median be a better measure of
central tendency for the following list of data?
6, 6, 7, 8, 9, 30
QuestionGiven the following frequency table of values, is the
mean or the median likely to be a better measure of the center of
the data set?
Value2021222324Frequency73325
QuestionGiven the following list of values, is the mean or
the median likely to be a better measure of the center of the data
set?
31, 32, 31, 34, 30, 30, 31, 31, 30, 31
QuestionGiven the following frequency table of values, is the
mean or the median likely to be a better measure of the center of
the data set?
Value40414243444546474849505152535455565758596061626364656667686970Frequency5612330000000000000000000000001
QuestionGiven the following frequency table of values, is the
mean or the median likely to be a better measure of the center of
the data set?
Value3233343536373839404142434445464748495051525354555657Frequency32302400000000000000000001
QuestionGiven the following list of values, is the mean or
the median likely to be a better measure of the center of the data
set?
26, 27, 26, 30, 27, 31, 29, 28, 53, 29
Determining the Best Measure of Center
Key Terms
•
Mean: the sum of all the items in a list divided by the number of
items in the list
The term Mean is often used interchangeably with the term
Average
•
Median: a number that splits a data set in half, with one half
smaller and one half larger; the center or middle value of a data
set
•
Mode: the number(s) that occurs most often in a data set
•
Outliers: values that are very different from the rest of the
values in a data set
QuestionGiven the following list of values, is the mean or
the median likely to be a better measure of the center of the data
set?
33, 33, 33, 31, 31, 34, 32, 31
QuestionGiven the following list of values, is the mean or
the median likely to be a better measure of the center of the data
set?
29, 56, 27, 29, 27, 28, 28, 30, 30, 27
QuestionEmily likes to catch and release fish in a pond and
record their lengths. Estimate the mean of the lengths (in inches)
of the fish given in the following grouped frequency table.
•
Round the final answer to two decimal places.
Value Interval
Frequency
2-5
10
6-9
12
10-13
6
14-17
7
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QuestionThe frequency table below summarizes a list of
recorded lengths (in inches) of randomly sampled fish in a pond.
Find the mean.
Value
Frequency
5
3
6
1
7
1
8
2
9
3
10
4
11
6
12
1
HelpCopy to ClipboardDownload CSV
QuestionA surveyor would like to find the mean number of pets
living in apartments in a city. He collects data from 36 apartments
in the area. The graph shows the frequency for the number of pets
living in the apartments.
Find the mean number of pets living in the 36 city
apartments, and round your answer to the nearest tenth. Record your
answer by dragging the purple point to the mean.
QuestionA student at Pine Valley high school would like to
find the mean number of extra credit points her fellow students
earned on a statistics chapter test. She collects data from 11
students in her class. The graph shows the frequency for the number
of extra credit points earned by her fellow classmates.
Find the mean number of extra credit points earned by the 11
students, and round your answer to the nearest tenth. Record your
answer by dragging the purple point to the mean.
QuestionFind the median of the numbers in the following list.
29,29,7,11,5,5
QuestionFind the mode of the following number of countries
randomly selected travelers visited in the past two years.
13,13,15,7,8,4,4,7,13
QuestionFind the median of the following list of inches
traveled by randomly selected worms in a two minute time period.
11,7,5,12,20,6
QuestionFind the mode of the following number of sweaters
purchased by randomly selected customers at a department store.
12,11,5,12,4,5,12,3
QuestionA trainer would like to find the mean number of
sports drinks the people in her class had in the last week. She
collects data from 26 participants in her aerobics class. The graph
shows the frequency for the number of sports drinks.
Find the mean number of sports drinks consumed by the 26
participants, and round your answer to the nearest tenth. Record
your answer by dragging the purple point to the mean.
QuestionGiven the following list of tips (in dollars) earned
in the last hour by waiters in a Japanese restaurant, find the
median.
30,17,47,47,26,17,36,31,21,17
QuestionGiven the following frequency table of values, is the
mean or the median likely to be a better measure of the center of
the data set?
Value202122232425262728293031323334353637Frequency100000000000034331
QuestionGiven the following list of values, is the mean or
the median likely to be a better measure of the center of the data
set?
39, 41, 38, 39, 38, 41, 41, 39, 40
QuestionA student would like to find the mean number of
people living in households in a neighborhood. He collects data
from 37 homes in the area. The graph shows the frequency for the
number of people living in the homes.
Find the mean number of people living in the 37 homes, and
round your answer to the nearest tenth. Record your answer by
dragging the purple point to the mean.
QuestionFind the median of the following list of dollars
spent per customer at a cheese shop in the last hour.
32,19,21,16,27,15
QuestionEstimate the mean of the amounts (in dollars)
randomly selected customers spent on chocolate chip cookies at a
winter fair given in the following grouped frequency table.
•
Round the final answer to one decimal place.
Value Interval
Frequency
0-3
5
4-7
6
8-11
13
12-15
1
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QuestionThe frequency table below summarizes a list of the
amounts (in dollars) randomly selected customers spent on hot
chocolate during a winter festival. Find the mean.
Value
Frequency
8
5
9
2
10
5
11
2
12
2
13
2
14
2
15
3
HelpCopy to ClipboardDownload CSV
QuestionFind the mode of the following amounts of exercise
(in hours) randomly selected runners completed during a weekend.
2,14,14,4,2,4,1,14,4,4,8
QuestionFind the mode of the following list of points earned
on a 16 point quiz given during a finance class.
7,7,3,2,7,16,12,16,12
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