Q67 of 91 Page 72

The mean of three numbers is 10. The mean of other four numbers is 12. Find the mean of all the numbers.

Mean of 3 numbers is 10


Sum of 3 numbers = Mean×3


Sum of 3 numbers = 30


Mean of other 4 numbers is 12


Sum of other 4 numbers = Mean×4


Sum of other 4 numbers = 48


Sum of all 7 numbers = 30 + 48 = 78


Mean of all 7 numbers =


= = 11.14


More from this chapter

All 91 →
65

Find the mean of first six multiples of 4.

 66

Find the median of first nine even natural numbers.

 68

Find the mode of the given data:

10, 8, 4, 7, 8, 11, 15, 8, 4, 2, 3, 6, 8

 69

Given below are heights of 15 boys of a class measured in cm:

128, 144, 146, 143, 136, 142, 138, 129, 140, 152, 144, 140, 150, 142, 154.


Find


A. The height of the tallest boy.


B. The height of the shortest boy.


C. The range of the given data.


D. The median height of the boys.