Advertisements
Advertisements
प्रश्न
Find the mean of each of the following frequency distributions
| Classes | 25 - 29 | 30 - 34 | 35 - 39 | 40 - 44 | 45 - 49 | 50 - 54 | 55 - 59 |
| Frequency | 14 | 22 | 16 | 6 | 5 | 3 | 4 |
उत्तर
Let the assume mean A = 42
| Classes | Mid value(x1) | d1 = x1 - 42 | `"u"_1=(x1-42)/5` | f1 | f1u1 |
| 25 - 29 | 27 | -15 | -3 | 14 | -42 |
| 30 - 34 | 32 | -10 | -2 | 22 | -44 |
| 35 - 39 | 37 | -5 | -1 | 16 | -16 |
| 40 - 44 | 42 | 0 | 0 | 6 | 0 |
| 45 - 49 | 47 | 5 | 1 | 5 | 5 |
| 50 - 54 | 52 | 10 | 2 | 3 | 6 |
| 55 - 59 | 57 | 15 | 3 | 4 | 12 |
| N = 70 | `sumf_1"u"_1=-79` |
We have
A = 42, h = 5
Mean `=A+hxx(sumf_1"u"_1)/N`
`=42+5xx(-79)/70`
`=42+(-395)/70`
`=42-395/70`
= 42 - 5.643
= 36.357
APPEARS IN
संबंधित प्रश्न
Thirty women were examined in a hospital by a doctor and the number of heartbeats per minute were recorded and summarized as follows. Fine the mean heartbeats per minute for these women, choosing a suitable method.
| Number of heartbeats per minute | 65 - 68 | 68 - 71 | 71 - 74 | 74 - 77 | 77 - 80 | 80 - 83 | 83 - 86 |
| Number of women | 2 | 4 | 3 | 8 | 7 | 4 | 2 |
If the mean of the following data is 15, find p.
| x | 5 | 10 | 15 | 20 | 25 |
| f | 6 | P | 6 | 10 | 5 |
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 |
Weight of 60 eggs were recorded as given below:
| Weight (in grams) | 75 – 79 | 80 – 84 | 85 – 89 | 90 – 94 | 95 – 99 | 100 - 104 | 105 - 109 |
| No. of eggs | 4 | 9 | 13 | 17 | 12 | 3 | 2 |
Calculate their mean weight to the nearest gram.
If the arithmetic mean of x, x + 3, x + 6, x + 9, and x + 12 is 10, the x =
If for certain frequency distribution, Median = 156 and Mode = 180, Find the value of the Mean.
There are 50 students in a class in which 40 are boys and rest are girls. The average weight of the class is 44 kgs and the average weight of the girls is 40 kgs. Find the average weight of the boys.
If xi’s are the midpoints of the class intervals of grouped data, fi’s are the corresponding frequencies and `barx` is the mean, then `sum(f_ix_i - barx)` is equal to ______.
Find the mean of: 5, 2.4, 6.2, 8.9, 4.1 and 3.4
The following table gives the marks scored by a set of students in an examination. Calculate the mean of the distribution by using the short cut method.
| Marks | Number of Students (f) |
| 0 – 10 | 3 |
| 10 – 20 | 8 |
| 20 – 30 | 14 |
| 30 – 40 | 9 |
| 40 – 50 | 4 |
| 50 – 60 | 2 |
