Mathematics
The mean of 5 numbers is 27. If one of the numbers be excluded, their mean is 25. The excluded number is :
25
26
28
35
Answer
Given,
Mean of 5 numbers = 27
Sum = Number of observations × Initial Mean
= 5(27)
= 135
When one number is excluded, 4 numbers remain, and their new mean is 25.
Sum of numbers(when one number is excluded) = Number of observations × new mean
= 4(25)
= 100
The difference between the two sums is the value of the number that was removed = 135 - 100 = 35
Hence, option 4 is the correct option.
Related Questions
Consider the table given below :
Marks Number of students 0 – 10 12 10 – 20 18 20 – 30 27 30 – 40 20 40 – 50 17 50 – 60 6 The mean of the marks given above is :
6
18
27
28
If the mean of the following distribution is 27, then the value of p is :
Class Frequency 0 – 10 8 10 – 20 p 20 – 30 12 30 – 40 13 40 – 50 10 6
7
9
11
For what value of x the mean of the given observations (2x − 5), (x + 3), (7 − x), (5 − x) and (x + 9) with frequencies 2, 3, 4, 6 and 1 respectively is 4?
1
2
3
4