A trader takes a sample of 50 eggs and weights them. The following table gives his findings: Weight of eggs in g 80 - 84 85 - 89 90 - 94 95 - 99 100 - 104 105 - 109 110 - 114 Frequency 2 6 12 14 10 5 1 If 10 eggs each weighing 100 g are added, what is the new mean weight? Calculate by using formula combined mean.

We construct the table of values is given as under: Classes Class mark x i Frequency f i d i = x i - A Where A = 97 u i = d i C where C = 50 f i u i 80 - 84 82 2 - 15 - 3 - 6 85 - 89 87 6 - 10 - 2 - 12 90 - 94 92 12 - 5 - 1 - 12 95 - 99 97 14 0 0 0 100 - 104 102 10 5 1 10 105 - 109 107 5 10 2 10 110 - 114 112 1 15 3 3 ∑ f i = 50 ∑ f i u i = - 7 Thus, by step deviation method, we have Mean = A + ∑ f i u i ∑ f i × C = 97 - 7 50 × 5 = 97 - 0 . 7 = 96 . 3 Therefore, required mean = 96 (nearest g ) N 1 = 50 , x ¯ 1 = 96 ; N 2 = 10 , x ¯ 2 = 100 Therefore, required mean = N 1 x ¯ 1 + N 2 x ¯ 2 N 1 + N 2 = 50 × 96 + 10 × 100 50 + 10 = 4800 + 1000 60 = 5800 60 = 96 . 7 g .

EASY

11th ICSE

IMPORTANT

Earn 100

For the following frequency distribution, find the mean daily wage of a worker of a factory:

Daily wage $(in ₹)$ Number of workers

More than $300$ $0$

More than $250$ $12$

More than $200$ $21$

More than $150$ $44$

More than $100$ $53$

More than $50$ $59$

More than $0$ $60$

Daily wage $(in ₹)$	Number of workers
More than $300$	$0$
More than $250$	$12$
More than $200$	$21$
More than $150$	$44$
More than $100$	$53$
More than $50$	$59$
More than $0$	$60$

50% studentsanswered this correctly

Important Questions on Statistics

MEDIUM

11th ICSE

IMPORTANT

Understanding ISC Mathematics Class 11 Volume 2>Chapter 14 - Statistics>EXERCISE>Q 15

The following table gives the daily wages of $50$ workers of a factory:

Wages $(in ₹)$	$25 - 30$	$30 - 35$	$35 - 40$	$40 - 45$	$45 - 50$	$50 - 55$	$55 - 60$
Number of workers	$2$	$1$	$5$	$9$	$21$	$10$	$2$

Calculate the average daily wages.

MEDIUM

11th ICSE

IMPORTANT

Understanding ISC Mathematics Class 11 Volume 2>Chapter 14 - Statistics>EXERCISE>Q 15

The following table gives the daily wages of $50$ workers of a factory:

Wages $(in ₹)$	$25 - 30$	$30 - 35$	$35 - 40$	$40 - 45$	$45 - 50$	$50 - 55$	$55 - 60$
Number of workers	$2$	$1$	$5$	$9$	$21$	$10$	$2$

If daily wages of all workers are increased by $₹ 8$ , what will be the new average daily wage?

EASY

11th ICSE

IMPORTANT

Understanding ISC Mathematics Class 11 Volume 2>Chapter 14 - Statistics>EXERCISE>Q 15

The following table gives the daily wages of $50$ workers of a factory:

Wages $(in ₹)$	$25 - 30$	$30 - 35$	$35 - 40$	$40 - 45$	$45 - 50$	$50 - 55$	$55 - 60$
Number of workers	$2$	$1$	$5$	$9$	$21$	$10$	$2$

If, instead, the daily wages of all workers are increased by $20 %$ , what will be the new average daily wage?

EASY

11th ICSE

IMPORTANT

Understanding ISC Mathematics Class 11 Volume 2>Chapter 14 - Statistics>EXERCISE>Q 16

A trader takes a sample of $50$ eggs and weights them. The following table gives his findings:

Weight of eggs $(in g)$	$80 - 84$	$85 - 89$	$90 - 94$	$95 - 99$	$100 - 104$	$105 - 109$	$110 - 114$
Frequency	$2$	$6$	$12$	$14$	$10$	$5$	$1$

Calculate the mean weight to the nearest $g$ .

EASY

11th ICSE

IMPORTANT

Understanding ISC Mathematics Class 11 Volume 2>Chapter 14 - Statistics>EXERCISE>Q 16

A trader takes a sample of $50$ eggs and weights them. The following table gives his findings:

Weight of eggs $(in g)$	$80 - 84$	$85 - 89$	$90 - 94$	$95 - 99$	$100 - 104$	$105 - 109$	$110 - 114$
Frequency	$2$	$6$	$12$	$14$	$10$	$5$	$1$

If $10$ eggs each weighing $100$ g are added, what is the new mean weight? Calculate by using formula combined mean.

MEDIUM

11th ICSE

IMPORTANT

Understanding ISC Mathematics Class 11 Volume 2>Chapter 14 - Statistics>EXERCISE>Q 17

The mean of the following distribution is $52 .$ Determine the value of $f :$

Marks	$10 - 20$	$20 - 30$	$30 - 40$	$40 - 50$	$50 - 60$	$60 - 70$	$70 - 80$
No. of Students	$5$	$3$	$4$	$f$	$2$	$6$	$13$

HARD

11th ICSE

IMPORTANT

Understanding ISC Mathematics Class 11 Volume 2>Chapter 14 - Statistics>EXERCISE>Q 18

The mean of the following distribution is $57.6$ and the sum of all the observations is $50 .$ Find the missing frequencies $f_{1}$ and $f_{2}$ :

Classes	$0 - 20$	$20 - 40$	$40 - 60$	$60 - 80$	$80 - 100$	$100 - 120$
Frequency	$7$	$f_{1}$	$12$	$f_{2}$	$8$	$5$

EASY

11th ICSE

IMPORTANT

Understanding ISC Mathematics Class 11 Volume 2>Chapter 14 - Statistics>EXERCISE>Q 19

Heights of

10

students were recorded and the mean was calculated as

155.3 cm .

Later, it was found that the height of two students was wrongly copied as

163

and

167

instead of

133

and

137

. Calculate the mean height in

cm

removing the incorrect heights and including the correct heights.

For the following frequency distribution, find the mean daily wage of a worker of a factory: Daily wage in ₹ Number of workers More than 300 0 More than 250 12 More than 200 21 More than 150 44 More than 100 53 More than 50 59 More than 0 60

Important Questions on Statistics

Learn and Prepare for any exam you want !

For the following frequency distribution, find the mean daily wage of a worker of a factory:

Daily wage $(in ₹)$ Number of workers

More than $300$ $0$

More than $250$ $12$

More than $200$ $21$

More than $150$ $44$

More than $100$ $53$

More than $50$ $59$

More than $0$ $60$