The weights (in kg) of 50 wrestlers are recor | vedclass

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(B) To find the mean weight,we use the assumed mean method. First,we determine the class marks $(x_i)$ for each class interval.						Weight (in $kg$)

Vedclass · Accepted Answer

$123.4$

Vedclass · Answer

(B) To find the mean weight,we use the assumed mean method. First,we determine the class marks $(x_i)$ for each class interval.						Weight (in $kg$)			Number of wrestlers $(f_i)$			Class Marks $(x_i)$			Deviations $(d_i = x_i - a)$			$f_i d_i$							$100-110$			$4$			$105$			$-20$			$-80$							$110-120$			$14$			$115$			$-10$			$-140$							$120-130$			$21$			$a = 125$			$0$			$0$							$130-140$			$8$			$135$			$10$			$80$							$140-150$			$3$			$145$			$20$			$60$							Total			$\Sigma f_i = 50$			-			-			$\Sigma f_i d_i = -80$			Let the assumed mean $(a) = 125$.Using the formula for the mean by the assumed mean method:Mean $(\bar{x}) = a + \frac{\Sigma f_i d_i}{\Sigma f_i}$$= 125 + \frac{-80}{50}$$= 125 - 1.6$$= 123.4 \ kg$.

Class	$1-3$	$3-5$	$5-7$	$7-9$	$9-11$
Frequency	$6$	$3$	$8$	$2$	$1$

Marks	Number of students
Below $10$	$3$
Below $20$	$12$
Below $30$	$27$
Below $40$	$57$
Below $50$	$75$
Below $60$	$80$

The weights (in $kg$) of $50$ wrestlers are recorded in the following table:

Weight (in $kg$) $100-110$ $110-120$ $120-130$ $130-140$ $140-150$

Number of wrestlers $4$ $14$ $21$ $8$ $3$

Find the mean weight of the wrestlers (in $kg$).

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Class $1-3$ $3-5$ $5-7$ $7-9$ $9-11$

Frequency $6$ $3$ $8$ $2$ $1$

In the formula $\bar{x} = A + \frac{\Sigma f_{i} u_{i}}{\Sigma f_{i}} \times c$ for the mean,$u_{i} = \ldots \ldots \ldots$

Midpoint (Midvalue) of the class $15-30$ is ........

For the following distribution,the modal class is:

Marks Number of students

Below $10$ $3$

Below $20$ $12$

Below $30$ $27$

Below $40$ $57$

Below $50$ $75$

Below $60$ $80$

The mean of $5$ observations is $16$. If an observation $5$ is replaced by $-5$,the new mean is ...........

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Weight (in $kg$)	$100-110$	$110-120$	$120-130$	$130-140$	$140-150$
Number of wrestlers	$4$	$14$	$21$	$8$	$3$

The weights (in $kg$) of $50$ wrestlers are recorded in the following table: Weight (in $kg$) $100-110$ $110-120$ $120-130$ $130-140$ $140-150$ Number of wrestlers $4$ $14$ $21$ $8$ $3$ Find the mean weight of the wrestlers (in $kg$).