CMA Foundation · Fundamentals of Business Mathematics and Statistics · Measures of Central Tendency and Dispersion
The monthly sales (in ₹ thousand) of a Kolkata retailer for five months are 10, 12, 14, 16 and 18. What is the population standard deviation (to two decimal places)?
The population standard deviation is 2.83. The mean is 14, the sum of squared deviations is 40, and dividing by n=5 gives variance 8, whose square root is about 2.83. Using n-1 would give the sample figure 3.16, which is not asked.
- A2.00
- B2.83Correct
- C4.00
- D3.16
Explanation
Mean = 70/5 = 14. Squared deviations: 16+4+0+4+16 = 40. Variance = 40/5 = 8, SD = √8 = 2.83. The value 3.16 comes from dividing by n-1 (√10), which is the sample SD, not the population SD asked for.
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