STATEMENT-1 : ∑ i = 1 9 x i - 8 = 9 and ∑ i = 1 9 x i - 8 2 = 45 , then S.D. of x 1 , x 2 , … … , x 9 is 2 STATEMENT-2 : S.D. is independent of change of origin

Statement-I is true, but Statement-II is false.

Statement-I is false, but Statement-II is true.

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The marks of some students were listed out of a maximum $100$ . The standard deviation of marks was found to be $9$ . Subsequently the marks raised to a maximum of $150$ and standard deviation of new marks was calculated. The new standard deviation

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Important Questions on Statistics

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Alpha Question Bank for Engineering: Mathematics>Chapter 23 - Statistics>Exercise-2>Q 1

Find the arithmetic mean of

{}^{2 n + 1}C_{0}, {}^{2 n + 1}C_{1}, \dots \dots . .^{2 n + 1} C_{n}

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Alpha Question Bank for Engineering: Mathematics>Chapter 23 - Statistics>Exercise-2>Q 2

Following is the record of goals scored by team $A$ in football session

Numbers of goals scored	$0$	$1$	$2$	$3$	$4$
Numbers of match is	$1$	$9$	$7$	$5$	$3$

for team $‘ B ’$ mean number of goals scored per match was $2$ goals with standard deviation $1.25$ . The team which is more consistent

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Alpha Question Bank for Engineering: Mathematics>Chapter 23 - Statistics>Exercise-2>Q 3

The mean of two samples of sizes

200

and

300

were found to be

25, 10

, respectively. Their standard deviations were

3

and

4

respectively. Find the variance of combined sample of size

500

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Alpha Question Bank for Engineering: Mathematics>Chapter 23 - Statistics>Exercise-2>Q 4

The first of the two samples have

100

items with mean

15

and

S . D . 3 .

If the whole group has

250

items with mean

15.6

and

S . D . = \sqrt{13.44}

then

S . D .

of the second group is

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Alpha Question Bank for Engineering: Mathematics>Chapter 23 - Statistics>Exercise-2>Q 5

The average marks of

10

students in a class was

60

with standard deviation

4 .

While the average marks of other

10

students was

40

with a standard deviation

6 .

If all the

20

students are taken together, their standard deviation will be

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Alpha Question Bank for Engineering: Mathematics>Chapter 23 - Statistics>Exercise-2>Q 6

The mean and variance of

5

observations of an experiment are

4

and

5.2

, respectively. From these observations three are

1, 2

and

6

and

λ = |x_{1} - x_{2}| + 8

where

x_{1} & x_{2}

are remaining observations, then number of solution of equation

10 - x^{2} - 2 x = λ

are

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Alpha Question Bank for Engineering: Mathematics>Chapter 23 - Statistics>Exercise-2>Q 7

The mean and variance of

10

numbers were calculated as

11.3

and

3.3

, respectively. It was subsequently found that one of the number was misread as

10

instead of

12 .

How does the variance change?

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Alpha Question Bank for Engineering: Mathematics>Chapter 23 - Statistics>Exercise-2>Q 10

STATEMENT-1 : $\sum_{i = 1}^{9} (x_{i} - 8) = 9$ and $\sum_{i = 1}^{9} {(x_{i} - 8)}^{2} = 45$ , then S.D. of $x_{1}, x_{2}, \dots \dots, x_{9}$ is $2$

STATEMENT-2 : S.D. is independent of change of origin

The marks of some students were listed out of a maximum 100. The standard deviation of marks was found to be 9. Subsequently the marks raised to a maximum of 150 and standard deviation of new marks was calculated. The new standard deviation

Important Questions on Statistics

Learn and Prepare for any exam you want !

The marks of some students were listed out of a maximum $100$ . The standard deviation of marks was found to be $9$ . Subsequently the marks raised to a maximum of $150$ and standard deviation of new marks was calculated. The new standard deviation