MCQs Basic Statistics Quiz 19

This Statistics Test is about MCQs Basic Statistics Quiz with Answers. There are 20 multiple-choice questions from Basics of Statistics, measures of central tendency, measures of dispersion, Measures of Position, and Distribution of Data. Let us start with the MCQS Basic Statistics Quiz with Answers

Online Multiple-Choice Questions about Basic Statistics with Answers

1. If 6 is multiple t all observations in the data, the mean is multiplied by

 
 
 
 

2. Which of the following is a relative measure of dispersion

 
 
 
 

3. For a set of distributions if the value of the mean is 20 and the mode is 14 then what is the value of the median for a set of distributions?

 
 
 
 

4. Two sets of distribution are as follows. For both of the sets, the Range is the same. Which of the demerits of Range is shown here in these sets of distribution?
Distribution 1: 30 14 18 25 12
Distribution 2: 30 7 19 27 12

 
 
 
 

5. The difference between the largest and smallest value in the data is called

 
 
 
 

6. Which of the following is an absolute measure of dispersion

 
 
 
 

7. The first step in computing the median is

 
 
 
 

8. The median is larger than the arithmetic mean when

 
 
 
 

9. If any value in the data is negative, it is not possible to calculate

 
 
 
 

10. Which of the properties of Average Deviation considers Mathematics assumption wrong?

 
 
 
 

11. The most important measure of dispersion is

 
 
 
 

12. If $x=3$ then which of the following is the minimum

 
 
 
 

13. Fill in the missing words to the quote: “Statistical methods may be described as methods for drawing conclusions about —————- based on ————– computed from the —————“.

 
 
 
 

14. Mode of the values 3, 5, 8, 10, and 12 is

 
 
 
 

15. The dispersion expressed in the form of a ratio or coefficient and independent from units of measurement is called

 
 
 
 

16. The half of the difference between the third and first quartiles is called

 
 
 
 

17. What would be the changes in the standard deviation if different values are increased by a constant?

 
 
 
 

18. Who used the term Statistics for the first time?

 
 
 
 

19. Mode of the values 2, 6, 8, 6, 12, 15, 18, and 8 is

 
 
 
 

20. In general, which of the following statements is FALSE?

 
 
 
 

Online MCQs Basic Statistics Quiz

  • If any value in the data is negative, it is not possible to calculate
  • Mode of the values 2, 6, 8, 6, 12, 15, 18, and 8 is
  • Mode of the values 3, 5, 8, 10, and 12 is
  • The first step in computing the median is
  • If $x=3$ then which of the following is the minimum
  • The dispersion expressed in the form of a ratio or coefficient and independent from units of measurement is called
  • The half of the difference between the third and first quartiles is called
  • The difference between the largest and smallest value in the data is called
  • The most important measure of dispersion is
  • Which of the following is a relative measure of dispersion
  • Which of the following is an absolute measure of dispersion
  • If 6 is multiple t all observations in the data, the mean is multiplied by
  • Which of the properties of Average Deviation considers Mathematics assumption wrong?
  • What would be the changes in the standard deviation if different values are increased by a constant?
  • Two sets of distribution are as follows. For both of the sets, the Range is the same. Which of the demerits of Range is shown here in these sets of distribution? Distribution 1: 30 14 18 25 12 Distribution 2: 30 7 19 27 12
  • For a set of distributions if the value of the mean is 20 and the mode is 14 then what is the value of the median for a set of distributions?
  • Who used the term Statistics for the first time?
  • The median is larger than the arithmetic mean when
  • Fill in the missing words to the quote: “Statistical methods may be described as methods for drawing conclusions about —————- based on ————– computed from the —————“.
  • In general, which of the following statements is FALSE?
MCQs Basic Statistics Quiz with Answers

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MCQs Basic Statistics Quiz 18

This post is about the MCQs Basic Statistics Quiz with Answers. There are 20 multiple-choice questions about the Basics of Statistics, covering measures of central tendency (Mean, Median, Mode, Geometric Mean, and Harmonic Mean), Measures of Dispersion, Deviations, Relationships between different measures of central tendency, Coding Methods for computing Mean, etc. Let us start with the MCQs Basic Statistics Quiz.

Please go to MCQs Basic Statistics Quiz 18 to view the test

MCQs Basic Statistics Quiz

  • One type of average is
  • The most central value of an array is called
  • In the case of an Open-end frequency table, the average cannot be computed accurately
  • One type of average is
  • The value obtained by dividing the sum of the values by their number is called
  • The arithmetic mean of 5, 9, 12, 15 is
  • The arithmetic mean of 112, 120, 135, 150, 157 is
  • The appropriate average for calculating the average percentage increase in population is
  • The arithmetic mean is affected by
  • The mean of the $n$ natural numbers is
  • The sum of deviations of the values from their means is
  • The sum of squares of deviations of the values is least when deviations are taken from
  • If the mean is greater than the mode, the distribution is
  • If $\Sigma (x – 12) = 0$ then $x=$
  • The Geometric Mean of $a$ and $b$ is
  • The sum of absolute deviations of the values is least when deviations are taken from
  • The coding method is used for calculating
  • The coding method is used for calculating
  • The relation between AM, GM, and HM is
  • If 4 is added to all observations in the data then the mean increases by
  • One type of average is
  • The most central value of an array is called
  • In the case of an Open-end frequency table, the average cannot be computed accurately
  • One type of average is
  • The value obtained by dividing the sum of the values by their number is called
  • The arithmetic mean of 5, 9, 12, 15 is
  • The arithmetic mean of 112, 120, 135, 150, 157 is
  • The appropriate average for calculating the average percentage increase in population is
  • The arithmetic mean is affected by
  • The mean of the $n$ natural numbers is
  • The sum of deviations of the values from their means is
  • The sum of squares of deviations of the values is least when deviations are taken from
  • If the mean is greater than the mode, the distribution is
  • If $\Sigma (x – 12) = 0$ then $x=$
  • The Geometric Mean of $a$ and $b$ is
  • The sum of absolute deviations of the values is least when deviations are taken from
  • The coding method is used for calculating
  • The coding method is used for calculating
  • The relation between AM, GM, and HM is
  • If 4 is added to all observations in the data then the mean increases by
Online MCQs Basic Statistics Quiz with Answers

General Knowledge Quiz, Data Analysis in R Language

Quartile Deviation (2025)

Quartile deviation denoted by QD is the absolute measure of dispersion and it is defined as the half of the difference between the upper quartile ($Q_3$) and the lower quartile ($Q_1$).

The Quartile Deviation also known as semi-interquartile range (Semi IQR), is a measure of dispersion that focuses on the middle 50% of the data. It is calculated as half the difference between the Third Quartile ($Q_3$) and the First Quartile ($Q_1$). One can write it mathematically as

$$QD = \frac{Q_3-Q_1}{2}$$

Note that the interquartile range is only the difference between the upper quartile ($Q_3$) and the lower quartile ($Q_1$), that is,

$$Interquartile\,\, Range = IRQ = Q_3 – Q_1$$

The Relative Measure of Quartile Deviation is the Coefficient of Quartile Deviation and is given as

$$Coefficient\,\,of\,\,QD = \frac{Q_3 – Q_1}{Q_3 + Q_1}\times 100$$

Quartile Deviation

When to Use QD

  • When dealing with skewed data or data with outliers.
  • When a quick and easy measure of dispersion is needed.

Interpretation QD

Spread: A larger quartile deviation indicates greater variability in the middle portion of the data.
Outliers: QD is less sensitive to extreme values (outliers) compared to the standard deviation.

Quartile Deviation for Ungrouped Data

222225253030303131333639
404042424848505152555759
818689899091919192939393
939494949596969697979898
999999100100100101101102102102102
102103103104104104105106106106107108
108108109109109110111112112113113113
113114115116116117117117118118119121

The above data is already sorted and there are a total of 96 observations. The first and third quartiles of the data can be computed as follows:

$Q_1 = \left(\frac{n}{4}\right)th$ value $= \left(\frac{96}{4}\right)th$ value $= 24th$ value. The 24th observation is 59, therefore, $Q_1=59$.

$Q_3 = \left(\frac{3n}{4}\right)th$ value $= \left(\frac{3\times 96}{4}\right)th$ value $= 72th$ value. The 72nd observation is 108, therefore, $Q_3=108$.

The quartile deviation will be

$$QD=\frac{Q_3 – Q_1}{2} = \frac{108-59}{2} = 24.5$$

The Interquartile Range $= IQR = Q_3 – Q_1 = 108 – 59 = 49$

The coefficient of Quantile Deviation will be

$$Coefficient\,\, of\,\, QD = \frac{Q_3 – Q_1}{Q_3 – Q_1}\times 100 = \frac{108-59}{108+59}\times 100 = 29.34\%$$

Quartile Deviation for Grouped Data

Consider the following example for grouped data to compute the quartile deviation.

ClassesFrequenciesClass BoundariesCF
11-14.91110.95-14.9511
15-20.91914.95-20.9530
21-24.92120.95-24.9551
25-30.93424.95-30.9585
31-34.91630.95-34.95101
35-40.9934.95-40.95110
41-44.9440.95-44.95114
Total114  

The first and third quartiles for the above-grouped data will be

\begin{align*}
Q_1 &= l + \frac{h}{f}\left(\frac{n}{4} – C\right)\\
&= 14.95 + \frac{6}{19}\left(\frac{114}{4} – 11\right)\\
&= 14.95 + \frac{6}{19}(28.5 – 11) = 20.48\\
Q_3 &= l + \frac{h}{f}\left(\frac{3\times 114}{4}-85\right)\\
&=30.95 + 0.187418 = 31.14
\end{align*}

The QD is

$$QD = \frac{Q_3 – Q_1}{2} = \frac{31.14 – 20.48}{2} = \frac{10.66}{2} = 5.33$$

The Interquartile Range will be

$$IQR = Q_3 – Q_1 = 31.14 – 20.48 = 10.66$$

The coefficient of quartile deviation is

$$Coefficient\,\,of\,\, QD = \frac{Q_3 – Q_1}{Q_3 + Q_1}\times 100 = \frac{31.14 – 20.48}{31.14+20.48}\times 100 = 20.65\%$$

  • Less affected by outliers: Makes it suitable for skewed data.
  • Easy to calculate: Relatively simple compared to standard deviation.

Disadvantages of QD

  • Ignores extreme values: This may not provide a complete picture of the data’s spread.
  • Less sensitive to changes in data: Compared to standard deviation.

In summary, Quartile deviation is a valuable and useful tool for understanding the spread of data, particularly when outliers are present. By focusing on the middle 50% of the data, it provides a robust measure of dispersion that is less sensitive to extreme values. However, it is important to consider its limitations, such as its insensitivity to outliers and changes in data.

Frequently Asked Questions about Quartile Deviation

  1. What is quartile deviation?
  2. What are the advantages of QD?
  3. What are the disadvantages of QD?
  4. What is IQR?
  5. What is Semi-IQR?
  6. How QD is interpreted?
  7. How QD is computed for grouped and ungrouped data?
  8. When QD should be used?

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