Question
Three colleagues, M, N, and O, have an average age of
27. Ten years ago, their ages were in the ratio of 4:6:7. What is the average age of M and N today?Solution
Sum of their present ages = 3 × 27 = 81 Sum of their ages before 10 years = 81-30 = 51 Let their ages 10 years ago were 4x, 6x and 7x Then, 4x+6x+7x = 51 17x = 51 x = 3 their ages 10 years ago were 12, 18, 21 present age of M = 12+10 = 22 present age of N = 18+10 = 28 average of present age of M and N = (28+22)/2 = 25
Following two statements are related to regression coefficient
(I) Independent of the change of origin
(II) Independent of the change of scale
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Which one is not basis of classification of data.
For making frequency distribution, the number of classes used depends upon:
Which option is incorrect?
Which of the following is the most relevant for deriving a point estimate?
The incomes of the employees in a state is assumed to be normally distributed with mean ₹15,000 and variance ₹900. The median of the distribution o...
The mean deviation from an average A will be minimum, if A represents:
The coefficient of correlation is the _________ of coefficients of regression.
For ANOVA table
the F - statistics is:
Two data set of size 9 and 6 have standard deviation 3 and 4 respectively and arithmetic means 3 and 3 respectively. The standard deviation of combined...
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