Advertisements
Advertisements
प्रश्न
The mean of three numbers is 10. The mean of other four numbers is 12. Find the mean of all the numbers.
Advertisements
उत्तर
Mean of three numbers = `"Sum of three numbers"/3`
⇒ `10 = "Sum of three numbers"/3` ...[∵ Mean of three numbers = 10, given]
Here, sum of three numbers = 30
Mean of other four numbers = `"Sum of other four numbers"/4`
⇒ `12 = "Sum of other four numbers"/4` ...`[(∵ "Mean of other four"),("numbers" = 12"," "given")]`
Hence, sum of other four numbers = 48
∴ Mean of all the numbers = `"Sum of all the numbers"/"Total numbers"`
= `(["Sum of first three numbers" + "Sum of other four numbers"])/7`
= `(30 + 48)/7`
= `78/7`
= 11.14
Hence, mean of all the numbers is 11.14.
APPEARS IN
संबंधित प्रश्न
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 |
The mean of 35 observations is 20, out of which mean of first 18 observations is 15 and mean of last 18 observation is 25. Find the 18th observation.
Mean of 100 observations is 40. The 9th observation is 30. If this is replaced by 70 keeping all other observations same, find the new mean.
Find the mean of first six multiples of 3.
Two vessels contain 20 liters and 60 liters of milk respectively. What is the amount that each vessel would have if both share the milk equally?
In a class test in mathematics, 10 students scored 75 marks, 12 students scored 60 marks, 8 students scored 40 marks and 3 students scored 30 marks. Find the mean of their score
The algebraic sum of the deviations of a set of n values from their mean is
The mean of first ten natural numbers is ____________
The average of the marks 2, 9, 5, 4, 4, 8, 10 is ____________
