Measures of Center & Spread

Match the following terms with their definitions

• Middle of the lower half of the data set. 25% of the data lies below this value and 75% lies above.

• Median (Q2)

• The lowest value of the data set

• Third Quartile (Q3)

• Middle of the data set. Half the data (50%) lies below this value and half (50%) lies above.

• First Quartile (Q1)

• Middle of the upper half of the data set. 75% of the data lies below this value and 25% lies below.

• Maximum (Max)

• The highest value of the data set

• Minimum (Min)

What percentage of the data is between 90 and 140?

• 25 %

• 50%

• 75%

• 100%

Given the data:

136, 150, 119, 150, 125, 140.

Find the upper quartile (Q3).

Mathematical Equivalence

ON

Which measure of center can be described as the average?

• Mean

• Median

• Mode

• Range

Which measure of center can be described as the middle?

• Mean

• Median

• Mode

• Range

Which measure of center can be described as the most common?

• Mean

• Median

• Mode

• Range

What is the median of the data set?
9, 7, 2, 4, 3, 5, 9, 6, 8, 0, 3, 8

• 6

• 7

• 5.5

• 9

What is the mean of the data set:
8.9, 9.4, 8.6, 9.1

• 8.5

• 8.9

• 9

• 9.1

At Donald's Donuts the number of donut holes in a bag can vary. Help Donald find the mode.
12,10,10,10,13,12,11,13,10

• 13

• 12

• 11

• 10

Find the standard deviation of the following
2, 5, 5, 8, 11, 12
to 3 s.f.

(a)