1.6 Mean, Median, Mode, and Range
vocab
measures of central tendency (aka measures of center) one number used to represent a set of data - mean,
median, and mode are measures of center
outlier a data value that is much higher or much lower that the other data values in
the data set (quartiles =/- 1.5iqr)
mean often reffered to as an average,
sum of data / numbers of values in the data set
most appropriate to use the mean to represent the data set when there are
no outliers in the data set
median the middle number in the data set ( data must be in numerical order to find the
middle number)
most appropriate to use to represent the data set when there are outliers in
the data set
mode most often occurring value in the data set
most appropriate to use mode to represent the data set when it is nonnumeric or when identifying the most popular item
range describes the spread of the data: maximum value - minimum value = range
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1. What information does this line plot provide?
2. What is a line plot?
3. Find the mean wage of the diner.
4. Find the median wage of the diner.
5. Find the mode wage of the diner.
6. What is the range of the wages?
7. Which measure of center best describes this data?
8. Could you answer #7 without answering 3 - 5?
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line plot a representation of a data set where values of the data set are plotted on a
number line
stem and leaf a representation of a data set where values are in a table each value is divided
into a stem and a leaf.
23
23
46 7
467
1. 5
1.5
4.3 6
4.36
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Gas prices from last summer are
displayed on the left.
1. Create a stem and leaf of those prices.
2. Find the mean of the prices.
3. Find the median of the prices.
4. Find the mode of the gas prices.
5. What is the range of the gas prices?
6. Which measure of center most accurately represnets the
data?
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last summer
this summer
$3.57
$3.85
$3.99
$3.64
$3.72
$3.77
$3.86
$3.93
1. Make a stem and leaf plot comparing the two summer's gas prices.
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Suppose you earned a 94, 82, and 89 on the last three tests in
Mr.V's class.
What do you need on the fourth test to have an average of 90?
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box and whiskers a representation of a data set that divides the data into quarters using
the five number summary
five number summary minimum, lower quartile, median, upper quartile, and maximum
minimum lowest value in the data set
lower quartile median of the lower half of the data set
median middle number in the data set
upper quartile median of the upper half of the data set
maximum largest value in the data set
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You can use a parallel
box and whiskers to
compare two sets of
data. This box-andwhiskers displays the
average monthly rainfall
for Miami and New
Orleans
1. Which city has more than 50% of there monthly averages above 120mm?
2. Which city has more than 75% of there monthly averages above 120mm?
3. The boxes represent the interquartile range ( the range between the
upper and lower quartiles). What do the widths of the boxes suggest about
the spread of the data around the median?
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The data at the right shows
snowboard prices at two
different shops.
1. Find the five number summary for the prices at Middletown
Snowboards.
2. Find the five number summary for the prices atSnowboard Central.
3. Create a parallel box-and-whikers plot of the two sets of snowboard
prices.
340
350
360
370
380
390
400
410
snowboard prices
4. Describe and compare the prices of the two different snowboard
companies. Use the proper vocabulary and five number summary in
your description. Use percentages or fractions to discuss the
distribution.
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