Advertisements
Advertisements
Question
The mean of 5 numbers is 18. If one number is excluded, the mean of the remaining number becomes 16. Find the excluded number.
Advertisements
Solution
Given the mean of 5 numbers is 18
The total sum of 5 numbers
= 18 x 5
= 90
On excluding an observation, the mean of remaining 4 observation is 16
= 16 x 4
= 64
Therefore the sum of the remaining 4 observations
total of 5 observations-total of 4 observations
= 90 - 64
= 26.
APPEARS IN
RELATED QUESTIONS
Find the mean of 43, 51, 50, 57 and 54.
Find the mean of the first six natural numbers.
Find the mean of all factors of 10.
Find x if 9, x, 14, 18 x, x, 8, 10 and 4 have a mean of 11.
Find the mean of 75 numbers, if the mean of 45 of them is 18 and the mean of the remaining ones is 13.
If different values of variable x are 9.8, 5.4, 3.7, 1.7, 1.8, 2.6, 2.8, 8.6, 10.5 and 11.1;
find
(i) the mean ` barx `
(ii) the value of ` sum (x_i - barx)`
If the mean of observations x, x + 2, x + 4, x + 6 and x + 8 is 11,
find:
(i) The value of x;
(ii) The mean of first three observations.
The mean of 16 numbers is 8. If 2 is added to every number, what will be the new mean?
The mean monthly salary of 10 members of a group is Rs.1,445, one more member whose monthly salary is Rs.1,500 has joined the group. Find the mean monthly salary of 11 members of the group.
If `bar"X"` is the mean of n observations x1, x2, x3,..., xn then the mean of `x_1/"a", x_2/"a", x_3/"a",...,x_"n"/"a" "is" bar"X"/"a"`, where a is an non-zero number.
i.e., if each observation is divided by a non-zero number, then the mean is also divided by it.
