CMA Foundation · Fundamentals of Business Mathematics and Statistics · Measures of Central Tendency and Dispersion
For a set of 20 observations arranged in ascending order, which position number (using (n+1) rule) corresponds to the 7th decile D7?
The 7th decile is at position 14.7. Using the formula 7(n+1)/10 with n = 20 gives 7 times 21 divided by 10, which equals 14.7, so the value lies 0.7 of the way between the 14th and 15th observations.
- A14.7Correct
- B14
- C15.4
- D13.3
Explanation
D7 position = 7(n+1)/10 = 7×21/10 = 14.7. The value 14 comes from using 7n/10 instead of 7(n+1)/10, and 15.4 from using 22 in place of 21.
Did you get it right without looking?
One question tells you little. A timed set on Measures of Central Tendency and Dispersion shows your real accuracy, how long you take and where you lose marks.
More Measures of Central Tendency and Dispersion questions
- For the data below, what is the arithmetic mean of daily output? Output: 10, 20, 30, 40 units with frequencies 5, 8, 4, 3 respectively.
- 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…
- In a moderately asymmetrical series, the median is 27 and the mode is 24. Using the empirical relation, the arithmetic mean is approximately…
- For a distribution, mean = 60 and standard deviation = 20, and Karl Pearson's coefficient of skewness (based on the mode) is +0.3. Assuming …
- The mean of 10 observations was calculated as 50. Later it was found that the value 82 was wrongly read as 28, and the value 35 was wrongly …
- For a moderately skewed distribution, the arithmetic mean is 42 and the median is 40. Using the empirical relationship among the three avera…