5.68 I FUNDAMENTALS OF BUSINESS MATHEMATICS AND STATISTICSMeasures of Central Tendency and Measures of Dispersion
- If 2xI + 3yI = 5 for I = 1, 2, ...., n and mean deviation of x 1 , x 2 , ....., xn about their mean is 12, find the
mean deviation of y 1 , y 2 , ...., yn about their mean.
[Ans.^193 ] - If the means of two groups of 30 and 50 observation are equal and their standard deviation are 8 and
4 respectively, find the grouped variance. [Ans.
5.83] - For 10 values x 1 , x 2 , ...., x 10 of a variable x,
10
∑i 1=xi=110, and ( )(^102)
∑i 1= x 5i− =1000, find
variance of x [Ans. 64]
- If the relations between two variables x and y be 2x – y + 3 = 0 and range of x be 10, then find the range
of y. [Ans. 20] - Runs made by two groups G 1 and G 2 of cricketers have means 50 and 40 and variance 49 and 36
respectively. Find which group is more constant in scoring runs. [Ans.
G 1 ] - If A.M. and coefficient of variation of a variable x are 10 and 50% respectively, find the variance of x.
[Ans. 25]