Advertisements
Advertisements
Question
Find the mean of the following frequency distribution :
| Class | 50-60 | 60-70 | 70-80 | 80-90 | 90-100 |
| Frequency | 8 | 6 | 12 | 11 | 13 |
Solution
| Class Interval | Xi | fi | fiXi |
| 50-60 | 55 | 8 | 440 |
| 60-70 | 65 | 6 | 390 |
| 70-80 | 75 | 12 | 900 |
| 80-90 | 85 | 11 | 935 |
| 90-100 | 95 | 13 | 1235 |
| Total | 50 | 3900 |
`barx = (Σf_iX_i)/(Σ"f")`
`barx = 3900/50`
`barx = 78`
`therefore` Mean = 78
APPEARS IN
RELATED QUESTIONS
Calculate the mean of the following distribution :
| Class Interval | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 |
| Frequency | 8 | 5 | 12 | 35 | 24 | 16 |
The mean of the number 6, ‘y’, 7, ‘x’ and 14 is 8. Express ‘y’ in terms of ‘x’.
The mean monthly income of 10 persons is Rs 8,670. If a new member with a monthly income of Rs 9, 000 joins the group, find the new monthly income.
Find the mean of the following frequency distribution by the step deviation method :
| Class | 100-110 | 110-120 | 120-130 | 130-140 | 140-150 |
| Frequency | 15 | 18 | 32 | 25 | 10 |
Find the median of all prime numbers between 20 and 50
The rainfall (in mm) in a city on 7 days of a certain week is recorded as follows:
| Day: | Mon | Tue | Wed | Thus | Fri | Sat | Sun |
| Rainfall (in mm): | 0.5 | 2.7 | 2.6 | 0.5 | 2 | 5.8 | 1.5 |
Find the total and average (mean) rainfall for the week.
Find the mean of: 12, 9, 6,11 and 17
If the mean of x, x + 2, x + 4, x + 6 and x + 8 is 13, find the value of x. Sum of data.
Find the median of 26, 33, 41, 18, 30, 22, 36, 45 and 24
The weekly sale of motor bikes in a showroom for the past 14 weeks given below. 10, 6, 8, 3, 5, 6, 4, 7, 12, 13, 16, 10, 4, 7. Find the median of the data.
