Lottery Sales
1. **Problem Statement:**
We have a frequency distribution of lottery sales over 30 days with class intervals and number of days as frequencies.
| No of lotteries | 150-250 | 250-350 | 350-450 | 450-550 | 550-650 | 650-750 | 750-850 |
| No of days | 3 | 2 | 5 | 9 | 3 | 6 | 2 |
We need to find:
(i) Modal class
(ii) Mean number of lotteries sold per day
(iii) Total commission received by the seller per day
(iv) Show that the distributor earns more than 26000 rupees in a month
2. **Step 1: Find the modal class**
The modal class is the class interval with the highest frequency (number of days).
Frequencies: 3, 2, 5, 9, 3, 6, 2
Maximum frequency = 9 corresponding to class 450-550
**Modal class = 450-550**
3. **Step 2: Find the mean number of lotteries sold per day**
We use the assumed mean method.
- Take the mid value of the modal class as assumed mean $A$.
Mid value of 450-550 = $\frac{450 + 550}{2} = 500$
- Calculate mid values ($x_i$) of all classes:
150-250: $\frac{150+250}{2} = 200$
250-350: $300$
350-450: $400$
450-550: $500$
550-650: $600$
650-750: $700$
750-850: $800$
- Calculate deviations $d_i = x_i - A$:
200 - 500 = -300
300 - 500 = -200
400 - 500 = -100
500 - 500 = 0
600 - 500 = 100
700 - 500 = 200
800 - 500 = 300
- Frequencies $f_i$: 3, 2, 5, 9, 3, 6, 2
- Calculate $f_i d_i$:
3*(-300) = -900
2*(-200) = -400
5*(-100) = -500
9*0 = 0
3*100 = 300
6*200 = 1200
2*300 = 600
- Sum of frequencies $\sum f_i = 3+2+5+9+3+6+2 = 30$
- Sum of $f_i d_i = -900 - 400 - 500 + 0 + 300 + 1200 + 600 = 300$
- Mean $\bar{x} = A + \frac{\sum f_i d_i}{\sum f_i} = 500 + \frac{300}{30} = 500 + 10 = 510$
- Rounded to nearest whole number: **510**
4. **Step 3: Calculate total commission received by the seller per day**
- Commission per lottery = 3 rupees
- Mean lotteries sold per day = 510
- Total commission per day = $3 \times 510 = 1530$
5. **Step 4: Show distributor earns more than 26000 rupees in a month**
- Selling price per lottery = 20 rupees
- Total sales per day = $20 \times 510 = 10200$
- Commission paid to seller per day = 1530 rupees
- Remaining amount per day = $10200 - 1530 = 8670$
- Distributor receives 10% of remaining amount:
$0.10 \times 8670 = 867$
- Distributor's monthly earning = $867 \times 30 = 26010$
- Since 26010 > 26000, distributor earns more than 26000 rupees in a month.
**Final answers:**
(i) Modal class = 450-550
(ii) Mean number of lotteries sold per day = 510
(iii) Total commission per day = 1530
(iv) Distributor earns 26010 rupees in a month, which is more than 26000