Descriptive Statistics

Which of the following is a measure of central tendency?

• Variance

• Standard Deviation

• Mean

• Range

The median of dataset (3 , 7 , 9 , 12 , 15 , 18 ) is:

• 9

• 10.5

• 12

• 11

Which measure is most affected by extreme values in a dataset?

• Median

• Mean

• Mode

• Interquartile range

Which of the following is NOT affected by extreme values in a dataset?

• Mean

• Standard deviation

• Median

• Range

The range of dataset is defined as:

• The difference between highest and lowest values

• The average of all values

• The middle value when data is ordered

• The most frequently occuring value

A dataset has the following five-number summary: {5, 10, 15, 20, 30}. What is the interquartile range (IQR)?

• 10

• 15

• 20

• 25

Answer explanation

Given five-number summary:

• Minimum (Q0): 5

• First quartile (Q1): 10

• Median (Q2): 15

• Third quartile (Q3): 20

• Maximum (Q4): 30

• Interquartile Range (IQR) Formula:

IQR=Q3−Q1

Calculation:

IQR=20−10=10

Which of the following best describes the mode?

• The sum of all values divided by the number of observations

• The middle value of an ordered dataset

• The most frequently occurring value in a dataset

• The difference between the highest and lowest values

Which graphical method is most suitable for displaying the distribution of a continuous variable?

• Bar chart

• Pie chart

• Histogram

• Line graph

If the mean is greater than the median in a dataset, the distribution is likely to be:

• Symmetric

• Positively skewed

• Negatively skewed

• Bimodal

Answer explanation

Which of the following measures is used to describe the dispersion or spread of data?

• Mean

• Interquartile range

• Standard deviation

• Mode