Let the mean and the standard deviation of th | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) Given observations: $2, 3, 3, 4, 5, 7, a, b$. Total number of observations $n = 8$.Mean $\bar{x} = \frac{2+3+3+4+5+7+a+b}{8} = 4 \implies 24 + a +

Vedclass · Accepted Answer

$1$

Vedclass · Answer

(A) Given observations: $2, 3, 3, 4, 5, 7, a, b$. Total number of observations $n = 8$.Mean $\bar{x} = \frac{2+3+3+4+5+7+a+b}{8} = 4 \implies 24 + a + b = 32 \implies a + b = 8$.Variance $\sigma^2 = (\sqrt{2})^2 = 2$.Formula for variance: $\sigma^2 = \frac{\sum x_i^2}{n} - (\bar{x})^2$.$2 = \frac{2^2+3^2+3^2+4^2+5^2+7^2+a^2+b^2}{8} - 4^2$.$2 = \frac{4+9+9+16+25+49+a^2+b^2}{8} - 16$.$18 = \frac{112 + a^2 + b^2}{8} \implies 144 = 112 + a^2 + b^2 \implies a^2 + b^2 = 32$.Since $(a+b)^2 = a^2 + b^2 + 2ab$,we have $8^2 = 32 + 2ab \implies 64 - 32 = 2ab \implies ab = 16$.Solving $a+b=8$ and $ab=16$,we get $(a-4)^2 = 0$,so $a=4, b=4$.The observations are $2, 3, 3, 4, 4, 4, 5, 7$. The mode is $4$ (appears $3$ times).Mean deviation about mode $= \frac{\sum |x_i - 4|}{8} = \frac{|2-4| + |3-4| + |3-4| + |4-4| + |4-4| + |4-4| + |5-4| + |7-4|}{8}$.$= \frac{2 + 1 + 1 + 0 + 0 + 0 + 1 + 3}{8} = \frac{8}{8} = 1$.

$x_i$	$6$	$12$	$18$	$24$	$30$	$36$	$42$
$f_i$	$4$	$7$	$9$	$18$	$15$	$10$	$5$

Let the mean and the standard deviation of the observations $2, 3, 3, 4, 5, 7, a, b$ be $4$ and $\sqrt{2}$ respectively. Then the mean deviation about the mode of these observations is:

Similar Questions

Let the mean of $6$ observations $1, 2, 4, 5, x,$ and $y$ be $5$ and their variance be $10$. Then their mean deviation about the mean is equal to $........$.

The mean deviation from the median of the data $16, 22, 3, 14, 5, 10, 8, 6, 11, 4$ is

For the following distribution,the mean deviation about the median is:
$x_i$ $6$ $12$ $18$ $24$ $30$ $36$ $42$
$f_i$ $4$ $7$ $9$ $18$ $15$ $10$ $5$

Let $\bar{X}$ and $M.D.$ be the mean and the mean deviation about $\bar{X}$ of $n$ observations $x_i,$ $i = 1, 2, \dots, n.$ If each of the observations is increased by $5,$ then the new mean and the mean deviation about the new mean,respectively,are

The mean deviation about the mean for the observations $ -1, 0, 4 $ is:

Vedclass Test Series

Exam Paper Generator

Online Exam Module