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In 100 numbers, 80 numbers are 4's and t...

In 100 numbers, 80 numbers are 4's and the rest are 9's then the standard deviation=

A

2.1

B

2.2

C

2

D

None

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The correct Answer is:
C
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DIPTI PUBLICATION ( AP EAMET)-MEASURES OF DISPERSION-EXERCISE-1
  1. The standard deviation of the following data is

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  2. The mean and variance of seven observations are 8 and 16 respectively....

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  3. The mean of 5 observations is 4.4 and their variance is 8.24. If three...

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  4. The arithmetic mean of the observations 10, 8, 5, a, b is 6 and their ...

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  5. The variance of 20 observations is 5. If each observations is multipli...

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  6. The mean of four observations is 3. If the sum of the squares of these...

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  7. If x(1), x(2),…..x(n) are n observations such that Sigmax(i)^(2)=400 a...

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  8. In 100 numbers, 80 numbers are 4's and the rest are 9's then the stand...

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  9. If the standard deviation of the number 2, 3, a and 11 is 3.5, then wh...

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  10. The mean of the data set comprising of 16 observations is 16. If one o...

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  11. The mean and standard deviation of 100 observations were calculated as...

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  12. The arithmetic mean and standard deviation of a set of 9 items are 43 ...

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  13. All the student of a class performed poorly in Mathematics. The teache...

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  14. The measure of dispersion which is used to find more consistent data i...

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  15. Two teams A and B have the same mean and their coefficients of varianc...

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  16. If standard deviation of a data is 3, arithmetic mean is 20, then coef...

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  17. If the mean of 10 observations is 50 and the sum of the squares of the...

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  18. Two plants A and B of a factory show following results about the numb...

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  19. An analysis of monthly wages paid to workers in two firms A and B, bel...

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  20. In a data the number I is repeated I times for i=1, 2, …,n. Then the m...

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