Understanding Measures of Position

Define quartiles in your own words.

• Quartiles are the average of the highest and lowest values in a dataset.

• Quartiles are values that divide a dataset into two equal parts.

• Quartiles are the middle values of a dataset when arranged in ascending order.

• Quartiles are values that split a dataset into four equal parts.

How do you calculate the third quartile (Q3) from a data set?

• Q3 is the average of the entire data set.

• Q3 is the median of the upper half of the data set.

• Q3 is the first quartile of the data set.

• Q3 is the minimum value of the data set.

Explain the difference between deciles and quartiles.

• Deciles are used for categorical data; quartiles are used for continuous data.

• Deciles and quartiles both divide data into equal parts but use different methods.

• Deciles divide data into five parts; quartiles divide data into three parts.

• Deciles divide data into ten parts; quartiles divide data into four parts.

What is the 90th percentile of the following data set: 1, 3, 5, 7, 9, 11, 13, 15, 17, 19?

• 17

• 13

• 15

• 19

Define percentiles and give an example.

• Percentiles are only applicable to normally distributed data.

• An example of a percentile is the 100th percentile, which is the maximum value in a dataset.

• The 50th percentile is the value above which 50% of the data points lie.

• An example of a percentile is the 90th percentile, which is the value below which 90% of the data points in a dataset lie.

How do you find the second quartile (Q2) in a data set?

• Q2 is the average of the data set.

• Q2 is the median of the data set.

• Q2 is the highest value in the data set.

• Q2 is the range of the data set.

How do you calculate the 25th percentile of a data set?

• Calculate the mean of the data set.

• Identify the maximum value in the data set.

• Find the median by sorting the data.

• Sort the data, then find the value at the position calculated by (N + 1) * 0.25.

What is the significance of the 50th percentile?

• The 50th percentile indicates the median value in a data set.

• The 50th percentile indicates the range of values in a data set.

• The 50th percentile is the average of all values in a data set.

• The 50th percentile represents the highest value in a data set.

Explain how to determine the position of a percentile in a data set.

• Use the formula P = (n * k) / 100 after sorting the data.

• Identify the mode of the data set.

• Calculate the mean of the data set.

• Count the total number of data points.