Advertisements
Advertisements
Question
The mean of 5 observations is 50. One of the observations was removed from the data, hence the mean became 45. Find the observation which was removed.
Advertisements
Solution
∴ Sum of observations = Mean × Total number of observations
⇒ sum of 5 observations = 50 × 5 = 250
Total no of observations when One of the observations was removed from the data = 4
⇒ sum of 4 observations = 45 × 4 = 180
So, the observation which was removed = sum of 5 observations − sum of 4 observations
250 − 180
= 70
The observation which was removed is 70.
APPEARS IN
RELATED QUESTIONS
A cricketer scores the following runs in eight innings:
58, 76, 40, 35, 46, 45, 0, 100
Find the mean score.
Following table shows the points of each player scored in four games:
| Player | Game 1 | Game 2 | Game 3 | Game 4 |
| A | 14 | 16 | 10 | 10 |
| B | 0 | 8 | 6 | 4 |
| C | 8 | 11 | Did not play | 13 |
Now answer the following questions:
- Find the mean to determine A’s average number of points scored per game.
- To find the mean number of points per game for C, would you divide the total points by 3 or by 4? Why?
- B played in all the four games. How would you find the mean?
- Who is the best performer?
The enrolment in a school during six consecutive years was as follows:
1555, 1670, 1750, 2013, 2540, 2820
Find the mean enrolment of the school for this period.
Solve any two of the following.
Find the mean of the data given in the following table.
| Class | 0-20 | 20-40 | 40-60 | 60-80 | 80-100 |
| Frequency | 6 | 4 | 5 | 7 | 3 |
If `barx` is the mean of x1, x2 ............xn and `bary` is the mean of y1, y2, …….yn and `barz` is the mean of x1, x2 ............xn, y1, y2, ……….yn then `barz` =?
The number of Science and Mathematics projects submitted by Model high school, Nandpur in last 20 years at the state level science exibition is:
2, 3, 4, 1, 2, 3, 1, 5, 4, 2, 3, 1, 3, 5, 4, 3, 2, 2, 3, 2. Prepare a frequency table and find the mean of the data.
Find the common difference of the A.P 3, 5, 7, ..........
Find the mean of first six multiples of 3.
The mean of the square of first 11 natural numbers is
The mean of a set of numbers is `bar(X)`. If each number is multiplied by z, the mean is
The marks of 14 students in a science test out of 50 are given below. 34, 23, 10, 45, 44, 47, 35, 37, 41, 30, 28, 32, 45, 39 Find the maximum mark obtained
The mean of first fifteen even numbers is ____________
Let x, y, z be three observations. The mean of these observations is ______.
Which measures of central tendency get affected if the extreme observations on both the ends of a data arranged in descending order are removed?
Calculate the Mean, Median and Mode of the following data:
5, 10, 10, 12, 13.
Are these three equal?
The marks in a subject for 12 students are as follows:
31, 37, 35, 38, 42, 23, 17, 18, 35, 25, 35, 29
For the given data, find the mean
The following are weights (in kg) of 12 people. 70, 62, 54, 57, 62, 84, 75, 59, 62, 65, 78, 60. How many people weigh above the mean weight?
