Advertisements
Advertisements
प्रश्न
Find the mean of the following data, using assumed-mean method:
| Class | 0 – 20 | 20 – 40 | 40 – 60 | 60 – 80 | 80 – 100 | 100 - 120 |
| Frequency | 20 | 35 | 52 | 44 | 38 | 31 |
उत्तर
| Class | Frequency `(f_i)` | Mid values `(x_i)` | Deviation `(d_i) d_i = (x_i – 50)` |
`(f_i × d_i)` |
| 0 –20 | 20 | 10 | -40 | -800 |
| 20 –40 | 35 | 30 | -20 | -700 |
| 40 –60 | 52 | 50=A | 0 | 0 |
| 60 – 80 | 44 | 70 | 20 | 880 |
| 80 – 100 | 38 | 90 | 40 | 1520 |
| 100 – 120 | 31 | 110 | 60 | 1860 |
| `Ʃ f_i `= 220 | `Ʃ (f_i × d_i) `= 2760 |
Let A = 50 be the assumed mean. Then we have:
Mean, x = A +`(Ʃ (f_i × d_i))/( Ʃ f_i)`
=50+`2760/220`
= 50+ 12.55
∴ x = 62.55
APPEARS IN
संबंधित प्रश्न
Consider the following distribution of daily wages of 50 worker of a factory.
|
Daily wages (in Rs) |
100 − 120 |
120 − 140 |
140 −1 60 |
160 − 180 |
180 − 200 |
|
Number of workers |
12 |
14 |
8 |
6 |
10 |
Find the mean daily wages of the workers of the factory by using an appropriate method.
If the mean of the following data is 15, find p.
| x | 5 | 10 | 15 | 20 | 25 |
| f | 6 | P | 6 | 10 | 5 |
If the mean of the following frequency distribution is 24, find the value of p.
| Class | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 |
| Frequency | 3 | 4 | p | 3 | 2 |
Find the mean age from the following frequency distribution:
| Age (in years) | 25 – 29 | 30 – 34 | 35 – 39 | 40 – 44 | 45 – 49 | 50 – 54 | 55 – 59 |
| Number of persons | 4 | 14 | 22 | 16 | 6 | 5 | 3 |
If the mean of frequency distribution is 8.1 and Σfixi = 132 + 5k, Σfi = 20, then k =?
The mean of the following distribution is
| xi | 10 | 13 | 16 | 19 |
| fi | 2 | 5 | 7 | 6 |
The average weight of a group of 25 men was calculated to be 78.4 kg. It was discovered later that one weight was wrongly entered as 69 kg instead of 96 kg. What is the correct average?
The mean of the following frequency distribution is 25. Find the value of f.
| Class | 0 – 10 | 10 – 20 | 20 – 30 | 30 – 40 | 40 – 50 |
| Frequency | 5 | 18 | 15 | f | 6 |
Find the mean of the following frequency distribution:
| Class | 1 – 5 | 5 – 9 | 9 – 13 | 13 – 17 |
| Frequency | 4 | 8 | 7 | 6 |
The lengths of 40 leaves of a plant are measured correct to the nearest millimeter, and the data obtained is represented in the following table:
| Length (in mm) | Number of leaves |
| 118−126 | 3 |
| 127–135 | 5 |
| 136−144 | 9 |
| 145–153 | 12 |
| 154–162 | 5 |
| 163–171 | 4 |
| 172–180 | 2 |
Find the mean length of the leaves.
