Tag: range and mean deviation

Questions Related to range and mean deviation

The coefficient of mean deviation from median of observations 40, 62, 54, 90, 68, 76 is

  1. 2.16

  2. 1.2

  3. 5

  4. none of these


Correct Option: B
Explanation:

Arranging the given data in ascending order
40,54,62,68,76,90
Here, $n=6 (even)$
$M= \dfrac{\text{value of }3^{rd}\text{observation}+\text{value of }4^{th}\text{observation}}{2}$
Median $M=\dfrac{62+68}{2}=65$

Mean deviation about median $M.D=\dfrac{|40-65|+|54-65|+|62-65|+|68-65|+|76-65|+|90-65|}{65}$

$=\dfrac{25+11+3+3+11+25}{65}=1.2$

The difference between the maximum and the minimum observations in the data is

  1. class interval

  2. frequency

  3. cumulative frequency

  4. range


Correct Option: D
Explanation:

The difference between maximum and the minimum observation in the data is range.

For example, suppose an experiment involves finding out the weight of lab rats and the values in grams are 320, 367, 423, 471 and 480. In this case, the range is simply computed as 480-320 = 160 grams.

The coefficient of range of a set of data is given to be $\dfrac18$. Then the ratio of the maximum value in the data to the minimum value is:

  1. $\dfrac81$

  2. $\dfrac98$

  3. $\dfrac97$

  4. $\dfrac87$


Correct Option: C
Explanation:

Coefficient of range of a set of data is given by $\dfrac{max-min}{max+min}$
$\dfrac{max-min}{max+min}=\dfrac{1}{8}$
$8max-8min=max+min$
$7max=9min$
$\dfrac{max}{min}=\dfrac{9}{7}$

The following are the wages of 8 workers in a factory. Find the range and coefficient of range. Wages are in dollars: 1400, 1450, 1520, 1380, 1485, 1495, 1575, 1440.

  1. $0.0231$

  2. $0.03112$

  3. $0.66$

  4. $0.02314$


Correct Option: C
Explanation:

The largest value of data is $x _m=1575$

The smallest value of data is $x _0=1380$
Range$=x _m-x _0=1575-1380=195$

Coefficient of data$=\dfrac{1575-1380}{1575+1380}=\dfrac{195}{2955}=0.0659\approx 0.66$

If the coefficient of range is $0.18$ and the largest value is $7.44$,then the smallest value is?

  1. $3.23$

  2. $4.15$

  3. $5.17$

  4. $5.14$


Correct Option: C
Explanation:

Coefficient of range$=\dfrac{x _m-x _0}{x _m+x _0}=\dfrac{7.44-x _0}{7.44+x _0}$

$0.18(7.44+x _0)=7.44-x _0$
$1.18x _0=7.44-7.44\times 0.18$
$1.18x _0=6.1008$
$x _0=5.17016\approx 5.17$

Find the coefficient of range for the data $43,24,38,56,22,39,45$

  1. $0124$

  2. $0.212$

  3. $0.236$

  4. $0.436$


Correct Option: D
Explanation:
Given data is $43, 24, 38, 56, 2, 39,45$.
The largest value of data is $x _m=56$
The smallest value of data is $x _0=22$
Coefficient of data $=\dfrac{56-22}{56+22}=\dfrac{34}{78}=0.4359\approx 0.436$
Hence, option D is correct.

The weight in Kg of 13 students in a class are $42.5,47.5,48.6,50.5,49,46.2,49.8,45.8,43.2,48,44.7,46.9,42.4$.Find the coefficient of range.

  1. $0.077$

  2. $0.213$

  3. $0.0803$

  4. $0.093$


Correct Option: C
Explanation:

The largest value of data is $x _m=49.8$

The smallest value of data is $x _0=42.4$
Coefficient of data$=\dfrac{49.8-42.4}{49.8+42.4}=\dfrac{7.4}{92.2}=0.08026\approx 0.0803$

Find the coefficient of range for the given data
$59,46,30,23,27,40,52,35,29$

  1. $0.46$

  2. $0.44$

  3. $0.56$

  4. $0.124$


Correct Option: B
Explanation:
Given data is $59, 46, 30, 23, 27, 40, 52, 35, 29$.
The largest value of data is $x _m=59$
The smallest value of data is $x _0=23$
Coefficient of data $=\dfrac{59-23}{59+23}=\dfrac{36}{82}=0.49\approx 0.44$

The median of the following observations is
$10, 8, -9, -12, 15, 0, 23, -3, -2, 13, -24, 28, 35, 42$

  1. $4$

  2. $-2$

  3. $7$

  4. $-9.75$


Correct Option: A

When all the observations are same, the relation between A.M., G.M and H.M is _________.

  1. A.M. = G.M. = H.M.

  2. A.M. = G.M. > H.M.

  3. A.M. > G.M. > H.M.

  4. A.M. < G.M. < H.M.


Correct Option: A