Measures of Central Tendency

Measures of Central Tendency

Algebra 1

Mode

• May have no mode, one mode, or more than one mode. Two modes is called bimodal.

• Mode is not stable. Changing one number can dramatically change the mode.

• Useful when we want to know the most frequently occurring data value such as most requested song, shoe size, most watched show.

• May help to order the data if it is a large group.

Some text here about the topic of discussion

Multiple Choice

What is the mode of this data set?

• 10

• 7

• 18

• 9

Multiple Choice

At Donald's Donuts the number of donut holes in a bag can vary. Help Donald find the MODE.

12, 10, 10, 11, 8, 5, 13, 10, 9

• 10

• 13

• No Mode

Multiple Choice

The mode is the number ________________________.

• you see most

• you see least

• you don't see

• you see first

Fill in the Blank

The number of college credits being taken by a sample of 14 full-time college students for a semester are listed below. The mode is .

12 14 16 15 13 14 15 18 16 16 12 16 15 17

Median

• The median is the central value of an ordered distribution. An equal number of data values above and below the median.

• Uses position rather than the specific value of each data entry.

• If the data has extreme values, the median usually does not change.

• Often used as the average for house prices. One expensive home in the neighborhood wouldn't affect the median selling prices of the other homes.

Some text here about the topic of discussion

• add two values

• divide by 2

​

​Find the median without the 35 cents. One ounce of chips is considered a small serving. Is it reasonable to budget about $10.45 to serve the barbecue-flavored chips to 55 people?

Fill in the Blank

The number of college credits being taken by a sample of 14 full-time college students for a semester are listed below. The median is .

12 14 16 15 13 14 15 18 16 16 12 16 15 17

Fill in the Blank

The Law School Admission Test (LSAT) scores for a sample of seven students accepted into a law school is listed below. The median score is .

174 172 169 176 169 170 175

Multiple Choice

Some quantitative data sets do not have medians.

• True

• False

Multiple Choice

It doesn't matter if the data set is ordered when finding the median.

• True

• False

Multiple Choice

If a data set has an even number of data, is it true or false that the median is never equal to a value in the data set? Explain.

• True

• False

​For large ordered data sets, the middle of the data set can be found by using the formula below.

​

For an ordered data set of size n,

​

Position of the middle value = ​

Examples:

​

If n = 99​, then the middle value is in the position.

​

If n = 100, then the middle value is in the position.​

​What the difference between the orange and blue persons hieght.=RANGE

Multiple Choice

Whats the range of this data set....

3.7.8.11,2,7

• 9

• 11

• 7

• 2

Multiple Choice

Six baskets of apples weigh the following pounds each:

70, 68, 73, 78, 75, and 76

Find the RANGE.

• 9

• 8

• 7

• 10

Mean

• Most important of the three. It can be affected by exceptional values.

• μ - pronounced mew (population parameter)

• ∑ - sigma - means sum the following

Some text here about the topic of discussion

Example:

To graduate, Linda needs at least a B in biology. She did not do very well on her first three tests; however, she did well on the last four. Her scores are:

​

58 67 60 84 93 98 100​

​

Compute the mean and determine whether Linda's grade will be a B (80 - 89)​ or C (70 to 79).

Fill in the Blank

How hot does it get in Death Valley? The following data are taken from a study conducted by the National Park System, of which Death Valley is a unit. The ground temperatures (degrees Fahrenheit) were taken from May to November in the vicinity of Furnace Creek? Find the mode.

Fill in the Blank

How hot does it get in Death Valley? The following data are taken from a study conducted by the National Park System, of which Death Valley is a unit. The ground temperatures (degrees Fahrenheit) were taken from May to November in the vicinity of Furnace Creek? Find the median.

Fill in the Blank

How hot does it get in Death Valley? The following data are taken from a study conducted by the National Park System, of which Death Valley is a unit. The ground temperatures (degrees Fahrenheit) were taken from May to November in the vicinity of Furnace Creek? Find the mean.

Weighted Average

• Sometimes we want more importance, or weight, to some of the numbers when averaging.

• How our grades are averaged.

• Multiply each data value by the weight.

• Add the products.

• Divide the by the sum of the weights.​

Weighted Average

Example:

​

Suppose your midterm test score is 83 and your final exam score is 95. Using weights of 40% for the midterm and 60% for the final exam, compute the weighted average of your scores.

​

Do you have an A?​

​

​

Multiple Choice

Find the class grade for a student with grades: Test 89%, Quiz 92, Homework 86%, and Classwork 95%.
Tests are 60% of the grade, Quiz 15%, Homework is 10% of the grade, and Classwork is 15% of the grade.

• 89.25

• 91.55

• 90.05

• i don't know

MIXED PRACTICE

You're doing great!

Multiple Choice

At Camden's Donuts the number of donut holes in a bag can vary. Help Camden find the mode of the number of donut holes per bag described in the sample below:

12, 10, 10, 10, 13, 12, 11, 13, 10, 12, 13

• 13

• 12

• 11

• 10

Multiple Choice

On a container ship there were 30 small containers that each weighed 3 tons, 20 medium containers that each weighed 5 tons, and 10 large containers that each weighed 8 tons.

Find the mean weight of the containers on this ship.

• 4.5 tons

• 4 tons

• 5 tons

• 5.5 tons

Multiple Choice

Zerek bowled 7 games last weekend. His scores are: 155, 165, 138, 172, 127, 193, 142. What is Zerek's median score?

• 127

• 155

• 156

• 193

Multiple Choice

The heights of some students are given.

158cm 172cm 164cm

164cm 167cm 159cm

What is the range of the heights?

• 13cm

• 14cm

• 164cm

• 330cm

Multiple Choice

In the last 5 games, Kevin Durant scored 22, 22, 18, 12, and 21 points. What is Durant's mean score per game?

• 19 points per game

• 95 points per game

• 18.6 points per game

• 22 points per game

Multiple Choice

What do you do if there are two numbers in "the middle" when you are finding the median?

• Pick your favorite number

• Add the two numbers in the middle & then divide by two.

• They are both the median

• None of the above

Multiple Choice

Find the median, mode and range: 
3, 5, 7, 9, 11, 8, 3

• median:7  mode:3  range:10

• median:6  mode:3  range:7

• median:7  mode:3 range:8

Multiple Choice

Which number is not the mean, median, mode, or range of the data set 4, 3, 15, 11, 3, 8, 7, 5?

• 3

• 7

• 12

• 11

Fill in the Blank

The weights (in pounds) of ten pumpkins are 22, 21, 24, 24, 5, 24, 5, 23, 24, and 24.

What is the range of the pumpkin weights?

Fill in the Blank

The weights (in pounds) of ten pumpkins are 22, 21, 24, 24, 5, 24, 5, 23, 24, and 24.

What is the mean of the pumpkin weights?

Fill in the Blank

The weights (in pounds) of ten pumpkins are 22, 21, 24, 24, 5, 24, 5, 23, 24, and 24.

What is the mode of the pumpkin weights?

Fill in the Blank

The weights (in pounds) of ten pumpkins are 22, 21, 24, 24, 5, 24, 5, 23, 24, and 24.

What is the median of the pumpkin weights?

.

Draw

EMOJI DRAW-

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