Advertisements
Advertisements
Question
The mean of 4 observations is 20. If one observation is excluded, the mean of the remaining observations becomes 15. Find the excluded observation.
Solution
Since mean of 4 observation = 20
⇒ Sum of 4 observation
= 4 x 20
= 80
By excluding one observation,
the mean of the remaining 3 observations = 15
⇒ Sum of remaining 3 observation
= 3 x 15
= 45
∴ Excluded observation
= Sum of 4 observation - Sum of 3 observations
= 80 - 45
= 35.
APPEARS IN
RELATED QUESTIONS
The mean of 15 observations is 32. Find the resulting mean, if each observation is: Multiplied by 2
Find the mean of 8, 12, 16, 22, 10 and 4. Find the resulting mean, if the observations, given above, be: multiplied by 3 and then divided by 2.
The heights (in cm) of the volleyball players from team A and team B were recorded as:
Team A: 180, 178, 176, 181, 190, 175, 187
Team B: 174, 175, 190, 179, 178, 185, 177
Which team had a greater average height?
Find the median of team A and team B.
The mean weight of 60 students in a class is 40 kg. The mean weight of boys is 50 kg while that of girls is 30 kg. Find the number of boys and girls in the class.
The mean of x, x + 2, x + 4, x + 6 and x + 8 is 11, find the mean of the first three observations.
Calculate man of the following: 4, 6, 6, 6, 7, 7, 7, 7, 8, 8, 9, 9, 11, 3
The height of 8 students X in centimetres are given below:
148, 162, 160, 154, 170, 162, x, 152
If the mean height is 158, find x.
A test out of 25 marks was given to 16 students and marks scored are recorded below: 25, 8, 14, 20, 16, 22, 10, 15, 8, 7, 24, 18, 19, 6, 11, 14
In the report, marks were entered out of 50. What is the mean of the recorded marks in the report?
In History project, marks out of 20 were awarded to 8 students. The marks were as shown below:
14, 16, 18, 14, 16, 14, 12, 16
Find the mean marks.
The mean of 16 natural numbers is 48. Find the resulting mean, if each of the number is increased by 5
