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Two samples of sizes 60 and 90 have 52 a...

Two samples of sizes 60 and 90 have 52 and 48 as the respective A.Ms. and 9 and 12 as the respective S.Ds. Find the A.M and S.D. of the combined sample of size 150.

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The correct Answer is:
49.6, 11.1
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CHHAYA PUBLICATION-MEASURES OF DISPERSION -Exercise 3 (Long answer type questions)
  1. Find the standard deviation of the following :

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  2. Define S.D. Find the standard deviation from the following frequency d...

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  3. Two samples of sizes 60 and 90 have 52 and 48 as the respective A.Ms. ...

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  4. Calculate the A.M. and the mean deviation thereform, from the followin...

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  5. From the following data determine in which factory X or Y, there is gr...

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  6. An analysis of weekly wages (in Rs.) paid to workers in two firms A an...

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  7. Two distributions have the same mean Rs. 7500 and standard deviations ...

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  8. In two firms X and Y engaged in the same industry, the average monthly...

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  9. Two batsmen A and B made the following scores in a series of criket ma...

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  10. From the following data determine in which firm, A or B there is grea...

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  11. In two factories A and B engaged in the same industry in an area, the ...

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  12. From the data given below, state with reason which series is more vari...

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  13. Find the coefficient of variation of the following data :

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  14. Find the variance and coefficient of variation of the following freque...

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  15. Calculate the variance of the following distribution (correct upto 3 p...

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  16. Find the semi-interquartile range for the following distribution : ...

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  17. Calculate the appropriate measure of dispersion from the following dat...

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  18. The mean and variance of the six values of a variate are 8 and 8(2)/(3...

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  19. The first of the two samples has 100 items with mean 15 and S.D. 3. If...

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  20. The mean and S.D. of income of 50 men are Rs. 3200 and Rs. 525 respect...

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