alleryThe mean of a set of observations is found by:
ATaking the middle value after sorting them
BDividing the sum of the values by how many there are
CTaking the value that occurs most often
DSubtracting the smallest value from the largest
Answer & Solution
Correct answer: B. Dividing the sum of the values by how many there are
1. The mean, also called the average, summarises a whole set with one number.
2. It is the sum of the values of all the observations divided by the total number of observations.
3. So both the total and the count are needed before it can be worked out.
4. The middle value after sorting is the median, and the most frequent value is the mode.
5. Largest minus smallest is the range, which measures spread rather than centre.
_Source: syllabus Maths, Ch 13 'Statistics', S13.2 Mean of Grouped Data_
Keep practising Averages
Browse all Averages questions for AFCAT, or explore more Quantitative Aptitude topics.
Related questions
A batsman's average over 16 innings is 36. To raise the average to 38 in the 17th innings,The average of 15 numbers is 12. The first 8 average 11 and the last 8 average 14. The 8thIn a branch, 30 clerks average 60 marks and 20 officers average 70. The average of all 50 The average of 6 numbers is 8. If the number 12 is removed, the average of the remaining 5The class mark of the class interval 10-25 is:The average of 10 numbers is 45. A new number, 100, is added to the set. The new average iThe average of the first 10 natural numbers is:The three measures of central tendency are: