Advertisements
Advertisements
Question
Find the mean of the following frequency distribution:
| Class Interval | Frequency |
| 0 - 50 | 4 |
| 50 - 100 | 8 |
| 100 - 150 | 16 |
| 150 - 200 | 13 |
| 200 - 250 | 6 |
| 250 - 300 | 3 |
Solution
| Class - Interval | (x) | (f) | (fx) |
| 0 - 50 | 25 | 4 | 100 |
| 50 - 100 | 75 | 8 | 600 |
| 100 - 150 | 125 | 16 | 2,000 |
| 150 - 200 | 175 | 13 | 2,275 |
| 200 - 250 | 225 | 6 | 1,350 |
| 250 - 300 | 275 | 3 | 825 |
| `sumf` = 50 | `sumfx` = 7,150 |
∴ Mean = `(sumfx)/(sumf)`
= `(7150)/(50)`
= 143.
APPEARS IN
RELATED QUESTIONS
Find the value of p, if the mean of the following distribution is 20.
| x | 15 | 17 | 19 | 20+P | 23 |
| f | 2 | 3 | 4 | 5P | 6 |
The marks obtained out of 50, by 102 students in a Physics test are given in the frequency table below:
| Marks(x) | 15 | 20 | 22 | 24 | 25 | 30 | 33 | 38 | 45 |
| Frequency (f) | 5 | 8 | 11 | 20 | 23 | 18 | 13 | 3 | 1 |
Find the average number of marks.
Find the mean of each of the following frequency distributions
| Class interval | 50 - 70 | 70 - 90 | 90 - 110 | 110 - 130 | 130 - 150 | 150 - 170 |
| Frequency | 18 | 12 | 13 | 27 | 8 | 22 |
Find the mean of each of the following frequency distributions
| Class interval | 0 - 8 | 8 - 16 | 16 - 24 | 24 - 32 | 32 - 40 |
| Frequency | 5 | 6 | 4 | 3 | 2 |
Find the mean of each of the following frequency distributions
| Class interval | 10 - 30 | 30 - 50 | 50 - 70 | 70 - 90 | 90 - 110 | 110 - 130 |
| Frequency | 5 | 8 | 12 | 20 | 3 | 2 |
Find the mean of the following data using step-deviation method:
| Class | 500 – 520 | 520 – 540 | 540 – 560 | 560 – 580 | 580 – 600 | 600 – 620 |
| Frequency | 14 | 9 | 5 | 4 | 3 | 5 |
If the mean of frequency distribution is 8.1 and Σfixi = 132 + 5k, Σfi = 20, then k =?
In calculating the mean of grouped data, grouped in classes of equal width, we may use the formula `barx = a + (sumf_i d_i)/(sumf_i)` where a is the assumed mean. a must be one of the mid-points of the classes. Is the last statement correct? Justify your answer.
Find the mean of: 5, 2.4, 6.2, 8.9, 4.1 and 3.4
The distribution given below shows the runs scored by batsmen in one-day cricket matches. Find the mean number of runs.
| Runs scored |
0 – 40 | 40 – 80 | 80 – 120 | 120 – 160 | 160 – 200 |
| Number of batsmen |
12 | 20 | 35 | 30 | 23 |
