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MCQ (Single Correct Answer)

1

The variance of a set of 20 observations is 16 . If 7 is added to each observation, and then $\mathbf{5}$ is subtracted from each resulting observation, what will be the new standard deviation?

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2

If for a distribution of 20 items, $\sum(x-4)=10$ and $\sum(x-4)^2=85$ then the standard deviation is:

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3
If the standard deviation of $0,1,2,3 \cdots\cdots\cdots9$ is ' $k$ ' then the standard deviation of $10,11,12,13, \cdots\cdots\cdots\cdots19$ will be :
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4
If the mean of $4,7,2,8,6$ and $k$ is 7 . Then the mean deviation from the mean of these observations is
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5
The variance of 25 observations is 8 . If each observation is multiplied by 3 , then the new variance of the resulting observations is
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6

The mean of five observations is 4 and their variance is 5.2 . If three of these observations are 1, 2 and 6, then the other two observations are

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7

Let 'P' be the mean deviation of the first five odd natural numbers about their mean and 'Q' be the mean deviation of the first five prime numbers about their mean. The $$Q-P=$$

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8

The mean of the numbers $$a, b, 8,5,10$$ is 6 and the variance is 6.80 , then which of the following gives possible values of $$a$$ & $$b$$

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9

Consider the first 10 natural numbers. If we multiply each number by $$-$$1 and add 1 to each number, the variance of the numbers so obtained is

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