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.
Advertisements
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
Find the mean of x + 3, x + 5, x + 7, x + 9 and x + 11.
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 mean of x, x + 2, x + 4, x + 6 and x + 8 is 11, find the mean of the first three observations.
Find the mean of the following data: 30, 32, 24, 34, 26, 28, 30, 35, 33, 25
(i) Show that the sum of the deviations of all the given observations from the mean is zero.
(ii) Find the median of the given data.
The marks obtained by 10 students are listed below:
2, 5, 3, 8, 0, 9, x, 6, 1, 8
If the mean marks is 5, 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
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
The mean of 4 observations is 20. If one observation is excluded, the mean of the remaining observations becomes 15. Find the excluded observation.
A boy scored the following marks in various class tests during a term, each test being marked out of 20.
15, 17, 16, 7, 10, 12, 14, 16, 19, 12, 16
What is his mean marks?
