What is the standard deviation of the followi | vedclass

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Question

Class
			$f$
			${y_i}$
			
			$d = {y_i} - A,$

			$A = 25$
			
			${f_i}{d_i}$
			${f_i}d_i^2$
		
		
			$0-10$
			$1$
			$

Vedclass · Accepted Answer

$9$

Vedclass · Answer

Class
			$f$
			${y_i}$
			
			$d = {y_i} - A,$

			$A = 25$
			
			${f_i}{d_i}$
			${f_i}d_i^2$
		
		
			$0-10$
			$1$
			$5$
			$-20$
			$-20$
			$400$
		
		
			$10-20$
			$3$
			$15$
			$-10$
			$-30$
			$300$
		
		
			$20-30$
			$4$
			$25$
			$0$
			$0$
			$0$
		
		
			$30-40$
			$2$
			$35$
			$10$
			$20$
			$200$
		
		
			Total
			$10$
			 
			 
			$-30$
			$900$
		
	


${\sigma ^2} = \frac{{\sum {{f_i}} d_i^2}}{{\sum {{f_i}} }} - {\left( {\frac{{\sum {{f_i}} {d_i}}}{{\sum {{f_i}} }}} \right)^2}$

$=\frac{900}{10}-\left(\frac{-30}{10}\right)^{2}$

$\sigma^{2}=90-9=81 $

$\Rightarrow \sigma=9$

${x_i}$	$60$	$61$	$62$	$63$	$64$	$65$	$66$	$67$	$68$
${f_i}$	$2$	$1$	$12$	$29$	$25$	$12$	$10$	$4$	$5$

What is the standard deviation of the following series

class $0-10$ $10-20$ $20-30$ $30-40$

Freq $1$ $3$ $4$ $2$

Similar Questions

The data is obtained in tabular form as follows.

${x_i}$ $60$ $61$ $62$ $63$ $64$ $65$ $66$ $67$ $68$

${f_i}$ $2$ $1$ $12$ $29$ $25$ $12$ $10$ $4$ $5$

If the mean of the frequency distribution

Class: $0-10$ $10-20$ $20-30$ $30-40$ $40-50$

Frequency $2$ $3$ $x$ $5$ $4$

is $28$ , then its variance is $........$.

The frequency distribution:

$\begin{array}{|l|l|l|l|l|l|l|} \hline X & A & 2 A & 3 A & 4 A & 5 A & 6 A \\ \hline f & 2 & 1 & 1 & 1 & 1 & 1 \\ \hline \end{array}$

where $A$ is a positive integer, has a variance of $160 .$ Determine the value of $A$.

The mean and variance of $7$ observations are $8$ and $16,$ respectively. If five observations are $2, 4, 10,12,14,$ then the absolute difference of the remaining two observations is

The mean and variance of seven observations are $8$ and $16$, respectively. If $5$ of the observations are $2, 4, 10, 12, 14,$ then the product of the remaining two observations is

Class:	$0-10$	$10-20$	$20-30$	$30-40$	$40-50$
Frequency	$2$	$3$	$x$	$5$	$4$

What is the standard deviation of the following series class $0-10$ $10-20$ $20-30$ $30-40$ Freq $1$ $3$ $4$ $2$