Advertisements
Advertisements
प्रश्न
The mean of 200 observations is 20. It is found that the value of 180 is wrongly copied as 280. Find the actual mean.
उत्तर
Since mean of 200 observations = 20
⇒ Sum of 200 observations
= 200 x 20
= 4000
⇒ Incorrect sum = 4000
∴ Correct sum
= Incorrect sum - Incorrect value + Correct value
= 4000 - 280 + 180
= 3900
∴ Correct mean
= `"Correct sum"/"Total number of observations"`
= `(3900)/(200)`
= 19.5.
APPEARS IN
संबंधित प्रश्न
The mean of 15 observations is 32. Find the resulting mean, if the observation is: Increased by 60%
Find the mean of 8, 12, 16, 22, 10 and 4. Find the resulting mean, if the observations, given above, be: multiplied by 3.
Find the mean of 8, 12, 16, 22, 10 and 4. Find the resulting mean, if each of the observations, given above, be: increased by 25%
The average of n numbers x1, x2, x3 ….. xn is A. If x1 is replaced by ( x+ α )x1, x2, is replaced by ( x+ α )x2 and so on.
Find the new average.
The mean of 6 numbers is 42. If one number is excluded, the mean of the remaining number is 45. Find the excluded number.
The mean of 10 numbers is 24. If one number is included, the new mean is 25. Find the included number.
Find the mean and median of all the positive factors of 72.
For the set of numbers given below, find mean: 5, 7, 8, 4, 6
For the set of numbers given below, find mean: 3, 0, 5, 2, 6, 2
A boy scored the following marks in various class tests during a terminal exam, each test being marked out of 20.
17, 15, 16, 7, 10, 14, 12, 19, 16, 12
Find his average mean marks.
