If the mean of five observations x x 2 x 4 x 6 x 8 is 13 find the value of x and hence find the mean...

Question

If the mean of five observations x x 2 x 4 x 6 x 8 is 13 find the value of x and hence find the mean of the last three observations

Accepted Answer

We know that Number of observations 5 It is given that mean 13 We can write it as x x 2 x 4 x 6 x 85 13 On further calculation 5x 20 13 5 So we get 5x 20 65 By subtraction 5x 45 By division x 9 By substituting the value of x We know that the last three observations are 9 4 13 9 6 15 9 8 17 We know that Mean of last three observations 13 15 173 On further calculation Mean of last three observations 453 By division Mean of last three observations 15 Therefore the mean of last three observations is 15

RS Aggarwal Solutions Class 9 Mathematics Solutions for Mean Median And Mode Of Ungrouped Data Exercise 18A in Chapter 18 - Mean Median And Mode Of Ungrouped Data