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(C) To find the mean number of days,we first calculate the class mark $(x_i)$ for each interval using the formula: $x_i = \frac{	ext{Upper class limi

Vedclass · Accepted Answer

$12.48$

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(C) To find the mean number of days,we first calculate the class mark $(x_i)$ for each interval using the formula: $x_i = \frac{	ext{Upper class limit} + 	ext{Lower class limit}}{2}$.Using the assumed mean method with $a = 17$,we calculate $d_i = x_i - a$ and $f_i d_i$:Number of daysNumber of students $(f_i)$$x_i$$d_i = x_i - 17$$f_i d_i$$0-6$$11$$3$$-14$$-154$$6-10$$10$$8$$-9$$-90$$10-14$$7$$12$$-5$$-35$$14-20$$4$$17$$0$$0$$20-28$$4$$24$$7$$28$$28-38$$3$$33$$16$$48$$38-40$$1$$39$$22$$22$Total$\sum f_i = 40$$\sum f_i d_i = -181$The mean $\bar{x}$ is given by $\bar{x} = a + \frac{\sum f_i d_i}{\sum f_i}$.Substituting the values: $\bar{x} = 17 + \frac{-181}{40} = 17 - 4.525 = 12.475$.Rounding to two decimal places,the mean number of days is $12.48$ days.

Marks obtained	Number of students
More than or equal to $0$	$63$
More than or equal to $10$	$58$
More than or equal to $20$	$55$
More than or equal to $30$	$51$
More than or equal to $40$	$48$
More than or equal to $50$	$42$

Daily expenditure (in $Rs.$)	$100-150$	$150-200$	$200-250$	$250-300$	$300-350$
Number of households	$4$	$5$	$12$	$2$	$2$

Number of seats	$100-104$	$104-108$	$108-112$	$112-116$	$116-120$
Frequency	$15$	$20$	$32$	$18$	$15$

Similar Questions

In the formula $\bar{x} = a + \frac{\sum f_{i} d_{i}}{\sum f_{i}}$ for finding the mean of grouped data,$d_{i}$ are deviations from $a$ of:

In calculating the mean of grouped data,grouped in classes of equal width,we may use the formula $\bar{x} = a + \frac{\sum f_i d_i}{\sum f_i}$,where $a$ is the assumed mean. $a$ must be one of the mid-points of the classes. Is the last statement correct? Justify your answer.

The table below shows the daily expenditure on food of $25$ households in a locality.
Daily expenditure (in $Rs.$) $100-150$ $150-200$ $200-250$ $250-300$ $300-350$
Number of households $4$ $5$ $12$ $2$ $2$

Find the mean daily expenditure on food by a suitable method.

An aircraft has $120$ passenger seats. The number of seats occupied during $100$ flights is given in the following table:

Number of seats $100-104$ $104-108$ $108-112$ $112-116$ $116-120$

Frequency $15$ $20$ $32$ $18$ $15$

Determine the mean number of seats occupied over the flights. (in $.92$)

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