Alpha Question Bank for Engineering: Mathematics>Chapter 23 - Statistics>Exercise-2>Q 11

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IMPORTANT

Earn 100

STATEMENT-I : Mean cannot be represented graphically.

STATEMENT-II : Mean may not coincide with anyone of the actual values.

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Important Questions on Statistics

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Alpha Question Bank for Engineering: Mathematics>Chapter 23 - Statistics>Exercise-2>Q 14

If the daily earnings (in rupees) of

12

workers in a factory are

16, 11, 3, 7, 5, 28, 9, 31, 28, 43, 15, 17,

then which of the following is(are) true?

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Alpha Question Bank for Engineering: Mathematics>Chapter 23 - Statistics>Exercise-2>Q 15

If first sample of

25

variates has the mean

40

and standard deviation

5

and a second sample of

35

variates has the mean

45

and standard deviation

2,

then which of the following is/are true

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Alpha Question Bank for Engineering: Mathematics>Chapter 23 - Statistics>Exercise-2>Q 16

Which of the following is false?

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Alpha Question Bank for Engineering: Mathematics>Chapter 23 - Statistics>Exercise-3>Q 1

The mean of the numbers

a, b, 8, 5, 10

is

6

and the variance is

6.80

. Then, which one of the following gives possible values of

a

and

b

?

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

Statement- $1 :$ The variance of first

n

even natural numbers is

\frac{n^{2} - 1}{4}

.
Statement- $2 :$ The sum of first

n

natural numbers is

\frac{n (n + 1)}{2}

and the sum of squares of first

n

natural numbers is

\frac{n (n + 1) (2 n + 1)}{6}

.

EASY

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

If the mean deviation of number

1, 1 + d, 1 + 2 d, \dots, 1 + 100 d

from their mean is

255

, then

d

is equal to

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Alpha Question Bank for Engineering: Mathematics>Chapter 23 - Statistics>Exercise-3>Q 4

For two data sets, each of size

5

, the variance are given to be

4

and

5

and the corresponding means are given to be

2

and

4

, respectively. The variance of the combined data set

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Alpha Question Bank for Engineering: Mathematics>Chapter 23 - Statistics>Exercise-3>Q 5

If the mean deviation about the median of the numbers

a, 2 a, . . ., 50 a

is

50,

then

|a|

equals