Statistics

Topics in this chapter

• Frequency Distributions
• Measures of Central Tendency
• Quartiles and Positional Measures
• Dispersion and Variability
• Data Transformations
• Correlation and Covariance
• Coefficient of Variation and Consistency
• Skewness and Interpretation

Cheat sheet

Practice questions

1. Question 1Q-E05B82

   The arithmetic mean of five observations is 12. If 3 is added to each observation, what will be the new arithmetic mean?

   1. A.9
   2. B.12
   3. C.15
   4. D.60
   See the answer and solution
2. Question 2Q-08F592

   The observations are 2, 4, 6 and 8. What is their standard deviation, using the population formula?

   1. A.2
   2. B.√5
   3. C.5
   4. D.√20
   See the answer and solution
3. Question 3Q-AE0661

   The covariance between variables X and Y is 12. If the standard deviations of X and Y are 3 and 8 respectively, what is their coefficient of correlation?

   1. A.0.25
   2. B.0.5
   3. C.2
   4. D.32
   See the answer and solution
4. Question 4Q-416463

   For the data 4, 7, 9, 12, 15, 18, 21, calculate the first quartile, third quartile and coefficient of quartile deviation.

   See the answer and solution
5. Question 5Q-7EB3EA

   Find the median of the observations 5, 17, 9, 13, 7, 15 and 11.

   1. A.9
   2. B.11
   3. C.13
   4. D.15
   See the answer and solution