brodidit for students
Measures of dispersion
Class 11 · Statistics · 12 questions
Name: ____________________ Date: ____________
The range of a set of data is the:
- A Largest value minus the smallest value
- B Middle value
- C Average of the values
- D Sum of all values
The standard deviation is the:
- A Square root of the variance
- B Mean of the values
- C Square of the variance
- D Half the range
The variance of 2, 4, 4, 4, 5, 5, 7 and 9 is:
- A 2
- B 4
- C 8
- D 32
The standard deviation of the same data is:
- A 4
- B 2
- C 5
- D 16
The coefficient of variation is:
- A Mean / SD
- B (SD / mean) x 100
- C Range / mean
- D SD x mean
A mean of 50 and a standard deviation of 5 give a coefficient of variation of:
- A 5%
- B 50%
- C 10%
- D 25%
The quartile deviation is:
- A Q1 / Q3
- B Q3 + Q1
- C (Q3 - Q1) / 2
- D Q3 x Q1
Which measure is least affected by extreme values?
- A Mean deviation
- B Quartile deviation
- C Range
- D Standard deviation
The range of 3, 5, 7, 8, 9, 11 and 13 is:
- A 10
- B 16
- C 8
- D 13
A series with a smaller coefficient of variation is:
- A Impossible
- B More consistent
- C Always larger
- D Less consistent
Which measure of dispersion uses every value of the data?
- A Quartile deviation
- B Standard deviation
- C Mode
- D Range
The sum of the deviations of the values from their mean is always:
- A Zero
- B One
- C The variance
- D Positive
Answer key
1. A, 2. A, 3. B, 4. B, 5. B, 6. C, 7. C, 8. B, 9. A, 10. B, 11. B, 12. A
It is the simplest measure of spread.
It has the same unit as the data.
The sum of squared deviations is 32, and 32 / 8 = 4.
The square root of 4.
It is a relative measure.
(5 / 50) x 100.
Half the interquartile range.
It uses only the middle half of the data.
13 - 3.
Its spread is small compared with its mean.
It is based on the deviations of all values.
That is why the deviations are squared.