Advertisements
Advertisements
प्रश्न
The following table gives the number of pages written by Sarika for completing her own book for 30 days:
| Number of pages written per day |
16 – 18 | 19 – 21 | 22 – 24 | 25 – 27 | 28 – 30 |
| Number of days | 1 | 3 | 4 | 9 | 13 |
Find the mean number of pages written per day.
उत्तर
No need to change the class-intervals into continuous intervals as Classmarks of continuous and discontinuous classes are same.
di is deviation from assumed mean.
| Class interval | Mid Value `(bb(x_i))` |
`bb(d_i = (x_i - a))` | No. of days `(bb(f_i))` |
`bb(f_i d_i)` |
| 16 – 18 | 17 | – 6 | 1 | – 6 |
| 19 – 21 | 20 | – 3 | 3 | – 9 |
| 22 – 24 | a = 23 | 0 | 4 | 0 |
| 25 – 27 | 26 | 3 | 9 | 27 |
| 28 – 30 | 29 | 6 | 13 | 78 |
| `sumf_i = 30` | `sumf_i d_i = 90` |
a = assumed mean, a = 23
`barx = a + (sumf_i d_i)/(sumf_i)`
= `23 + 90/30`
= 23 + 3
= 26
∴ `barx` = 26
Hence, the mean of pages written per day is 26.
APPEARS IN
संबंधित प्रश्न
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 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 |
There are three dealers A, B and C in Maharashtra. Suppose, the trade of each of them in september 2018 was as shown in the following table.
The rate of GST on each transaction was 5%.
Read the table and answer the questions below it.
| Dealer | GST collected on the sale |
GST paid at the time of purchase |
ITC | Tax paid to the Govt. |
Taxbalance with the Govt. |
| A | Rs.5000 | Rs. 6000 | Rs. 5000 | Rs. 0 | Rs. 1000 |
| B | Rs 5000 | Rs. 4000 | Rs. 4000 | Rs. 1000 | Rs. 0 |
| C | Rs.5000 | Rs. 5000 | Rs. 5000 | Rs. 0 | Rs. 0 |
(i) How much amount did the dealer A get by sale ?
(ii) For how much amount did the dealer B buy the articles ?
(iii) How much is the balance of CGST and SGST left with the government that was paid by A ?
If the arithmetic mean of x, x + 3, x + 6, x + 9, and x + 12 is 10, the x =
The mean of n observation is `overlineX`. If the first observation is increased by 1, the second by 2, the third by 3, and so on, then the new mean is
There are 45 students in a class, in which 15 are girls. The average weight of 15 girls is 45 kg and 30 boys is 52 kg. Find the mean weight in kg of the entire class.
The mean weight of 150 students in a certain class is 60 kgs. The mean weight of boys in the class is 70 kg and that of girls is 55 kgs. Find the number of boys and the number of girls in the class.
Mean of n numbers x1, x2, … xn is m. If xn is replaced by x, then new mean is ______.
The mileage (km per litre) of 50 cars of the same model was tested by a manufacturer and details are tabulated as given below:
| Mileage (km/l) | 10 – 12 | 12 – 14 | 14 – 16 | 16 – 18 |
| Number of cars | 7 | 12 | 18 | 13 |
Find the mean mileage. The manufacturer claimed that the mileage of the model was 16 km/litre. Do you agree with this claim?
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.
