EASY
11th CBSE
IMPORTANT
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Let x1,x2,xn be n observations. Let wi=lxi+k for i=1, 2,n where l and k are constants. If the mean of xi’s is 48 and their standard deviation is 12, the mean of wi 's is 55 and standard deviation of wi’s is 15, the values of l and k should be

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Important Questions on Statistics

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11th CBSE
IMPORTANT
Standard deviations for first 10 natural numbers is
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11th CBSE
IMPORTANT
Consider the numbers 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. If 1 is added to each number, the variance of the numbers so obtained is
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11th CBSE
IMPORTANT
Consider the first 10 positive integers. If we multiply each number by 1 and then add 1 to each number, the variance of the numbers so obtained is
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11th CBSE
IMPORTANT
The following information relates to a sample of size 60x2=18000, x=960 .Then, the variance is
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11th CBSE
IMPORTANT
If the coefficient of variation of two distributions are 50 and 60, and their arithmetic means are 30 and 25 respectively, then the difference of their standard deviation is
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11th CBSE
IMPORTANT
The standard deviation of some temperature data in C is 5. If the data were converted into F, the variance would be
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11th CBSE
IMPORTANT
Coefficient of variation is the ratio of ?
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11th CBSE
IMPORTANT

If x¯ is the mean of n values of x, then i=1nxi-x¯ is always equal to ?.If a has any value other than x¯, then i=1nxi-x¯2 is _____ than xi-a2.