Advertisements
Advertisements
Question
If the mean of 6, 4, 7, ‘a’ and 10 is 8. Find the value of ‘a’
Solution
No. of terms = 5
Mean = 8
Sum of numbers = 8 × 5 = 40 ...(i)
But, sum of number = 6 + 4 + 7 + a + 10 = 27 + a ...(ii)
From (i) and (ii)
27 + a = 40
a = 13
APPEARS IN
RELATED QUESTIONS
Calculate the mean of the following distribution using step deviation method.
| Marks | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 |
| Number of students |
10 | 9 | 25 | 0 | 16 | 10 |
1) Using step–deviation method, calculate the mean marks of the following distribution.
2) State the modal class.
| Class Interval | 50 - 55 | 55 - 60 | 60 - 65 | 65 - 70 | 70 - 75 | 75 - 80 | 80 - 85 | 85 – 90 |
| Frequency | 5 | 20 | 10 | 10 | 9 | 6 | 12 | 8 |
The mean of the following distribution is 62.8 and the sum of all the frequencies is 50. Find the missing frequencies f1 and f2.
| Class | 0 – 20 | 20 – 40 | 40 – 60 | 60 – 80 | 80 – 100 | 100 – 120 |
| Frequency | 5 | f1 | 10 | f2 | 7 | 8 |
What is the median of 7, 10, 7, 5, 9, 10?
Find the mean of first 10 prime numbers.
Find the mean of the following frequency distribution :
| Class | 1-10 | 11-20 | 21-30 | 31-40 | 41-50 |
| Frequency | 9 | 12 | 15 | 10 | 14 |
Draw a histogram for the following distribution and estimate the mode:
| Mangoes | 0-9 | 10-19 | 20-29 | 30-39 | 40-49 | 50-59 |
| No. of trees | 10 | 16 | 20 | 14 | 6 | 4 |
Estimate the median, the lower quartile and the upper quartile of the following frequency distribution by drawing an ogive:
| Age( in yrs) | Under 10 | Under 20 | Under 30 | Under 40 | Under 50 | Under 60 |
| No. of males | 6 | 10 | 25 | 32 | 43 | 50 |
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 median
Find the median of the given data if the mean is 4.5.
5, 7, 7, 8, x, 5, 4, 3, 1, 2
