Measures of central tendency

Written by Dr. Nadia Shah (Statistics)

Class 11 · Statistics · 12 questions

Name: ____________________ Date: ____________

The arithmetic mean of 2, 4, 6, 8 and 10 is:
- A 8
- B 6
- C 5
- D 30
The median of 3, 5, 7, 9 and 11 is:
- A 7
- B 35
- C 5
- D 9
The median of 4, 6, 8 and 10 is:
- A 7
- B 28
- C 8
- D 6
The mode of 2, 3, 3, 4, 3, 5 is:
- A 5
- B 2
- C 3
- D 4
Which average is least affected by extreme values?
- A The sum
- B The weighted mean
- C The median
- D The mean
The formula for the mean of a frequency distribution is:
- A Σx × Σf
- B Σx ÷ Σf
- C Σf ÷ Σfx
- D Σfx ÷ Σf
A set of data with two modes is called:
- A Unimodal
- B Skewed
- C Bimodal
- D Symmetric
Which average can be used for non-numerical data such as favourite colours?
- A The mean
- B The mode
- C The weighted mean
- D The median
The mean of 10, 20 and 30 is:
- A 60
- B 20
- C 30
- D 10
The sum of 5 values is 40. Their mean is:
- A 5
- B 35
- C 8
- D 200
A weighted mean is used when:
- A There is only one value
- B The values have different importance
- C The data are not numbers
- D All values are equal
The mean of the frequency distribution with values 1, 2 and 3 and frequencies 2, 3 and 5 is:
- A 2.3
- B 2
- C 1.5
- D 3

Answer key

1. B, 2. A, 3. A, 4. C, 5. C, 6. D, 7. C, 8. B, 9. B, 10. C, 11. B, 12. A

The sum is 30 and there are 5 values, so 30 ÷ 5 = 6.
The middle value of the five ordered values is 7.
With an even number of values the median is the mean of 6 and 8, which is 7.
3 occurs three times, more than any other value.
The median depends only on the middle position.
Multiply each value by its frequency, add them and divide by the total frequency.
Two values with the highest frequency make the data bimodal.
The mode is the most frequent category.
The sum is 60 and 60 ÷ 3 = 20.
40 ÷ 5 = 8.
Each value is multiplied by its weight.
Σfx = 2 + 6 + 15 = 23 and Σf = 10, so the mean is 2.3.