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They help in organizing data into tables.

They allow us to compare individual data points to the entire data set.

They are used only for calculating averages.

They are only useful for small data sets.

Quartiles, Deciles, Percentiles

Mean, Median, Mode

Range, Variance, Standard Deviation

Quartiles, Medians, Modes

Quartiles divide a ranked data into four equal parts.

Quartiles divide a ranked data into three equal parts.

Quartiles divide a ranked data into ten equal parts.

Quartiles divide a ranked data into two equal parts.

First Quartile

Second Quartile

Third Quartile

Upper Quartile

It is also called the median.

It divides the data so that 50% are below and 50% are above.

It is the 1/2(n+1)th observation in ascending order.

It is the lowest value in the data set.

3/4(n+1)th observation

1/4(n+1)th observation

1/2(n+1)th observation

n/4th observation

Q1 and Q3

Q2 and Q3

Q1 and Q2

Q2 and Q4

Q3 + Q1

Q3 - Q1

Q1 - Q3

Q3 × Q1

Calculate the mean

Find the median and quartiles

Count the number of data points

Subtract the smallest value from the largest

12, 12, 13, 13, 14, 15, 16, 16, 17, 18, 19, 20, 21, 22, 25

12, 13, 12, 16, 14, 15, 17, 19, 25, 21, 13, 16, 18, 20, 22

12, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 25, 13, 16

12, 12, 13, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 25, 16

Arrange the data in ascending order and determine the number of observations.

Calculate the mean of the data set.

Find the mode of the data set.

Group the data into intervals.

1/4(n + 1)

1/2(n + 1)

1/3(n + 1)

n/4

13

12

14

15

Q2 is found at the 8th observation.

Q2 uses the formula 1/2(n + 1).

Q2 is the median of the data set.

Q2 is always the smallest value in the data set.

Quartiles

Deciles

Percentiles

Means