Appropriate Measures of Central Tendency and Variability

Which best represents the Interquartile Range

• 15

• 93

• 85

• 78

The ____________ is the measure of central tendency that represents the middle number in a set of data.

• Mode

• Average

• Principal

• Median

In order to find the ____________, we add up all of the numbers in the data set and then divide the sum by the number of numbers.

• Average

• Mode

• Upper Quartile

• Median

The number that appears the most in a data set is commonly known as the ___________.

• Mean

• Range

• Mode

• Average

The median of the top 50% of the number values in the data set is known as the _________________.

• Upper Extreme

• Principal

• Upper Quartile

• Range

How do we find the median when there are exactly TWO numbers in the middle of the data set?

• We add up all of the numbers and divide by the number of numbers.

• Subtract the lower extreme from the upper extreme.

• Add the two numbers together and divide the sum by 2.

• Use the formula I = P x r x t

The following data set represents the responses from students when they were asked how many siblings they had: 1, 1, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 4, 7 What is the average number of siblings for this set of students?

• About 2.6

• 6

• About 18

• About 2.4

Measures of Central Tendency help us to relate numbers in a set of data to each other. For example, if the average student’s grade in your math class is an 81, we know that someone who has a grade of 97 is performing well ABOVE the average in that class. Amongst the following choices, which grade would represent a student performance that is considered well BELOW average?

• 80

• 75

• 77

• 62

The ______________ can be found by subtracting the lower extreme from the upper extreme.

• Range

• Median

• Mean

• Rate

The number of pages that Carolyn wrote in her journal each day from Monday to Friday is shown below: 
9, 8, 12, 6, 10
What is the mean number of pages she wrote per day?

• 5

• 6

• 9

• 11