Advertisements
Advertisements
Question
Find the mode of the following distribution.
| Class-interval: | 0 - 10 | 10 - 20 | 20 - 30 | 30 - 40 | 40 - 50 | 50 - 60 | 60 - 70 | 70 - 80 |
| Frequency: | 5 | 8 | 7 | 12 | 28 | 20 | 10 | 10 |
Solution
| Class-interval: | 0 - 10 | 10 - 20 | 20 - 30 | 30 - 40 | 40 - 50 | 50 - 60 | 60 - 70 | 70 - 80 |
| Frequency: | 5 | 8 | 7 | 12 | 28 | 20 | 10 | 10 |
L = 40, h = 50 - 40 = 10, f = 28, f1 = 12 and f2 = 20
Mode `=L+(f-f_2)/(2f-f_1-f_2)xxh`
`=40+(28-12)/(2xx28-12-20)xx10`
`=40+(16xx10)/24`
`=40+160/24`
= 40 + 6.67
= 46.67
APPEARS IN
RELATED QUESTIONS
The following data gives the information on the observed lifetimes (in hours) of 225 electrical components:
| Lifetimes (in hours) | 0 − 20 | 20 − 40 | 40 − 60 | 60 − 80 | 80 − 100 | 100− 120 |
| Frequency | 10 | 35 | 52 | 61 | 38 | 29 |
Determine the modal lifetimes of the components.
The agewise participation of students in the annual function of a school is shown in the following distribution.
| Age (in years) | 5 - 7 | 7 - 9 | 9 - 11 | 11 – 13 | 13 – 15 | 15 – 17 | 17 – 19 |
| Number of students | x | 15 | 18 | 30 | 50 | 48 | x |
Find the missing frequencies when the sum of frequencies is 181. Also find the mode of the data.
State the modal class.
| Class Interval | 50 - 55 | 55 - 60 | 60 - 65 | 65 - 70 | 70 - 75 | 75 - 80 | 80 - 85 | 85 - 90 |
| Frequency | 5 | 20 | 10 | 10 | 9 | 6 | 12 | 8 |
A study of the yield of 150 tomato plants, resulted in the record:
| Tomatoes per Plant | 1 - 5 | 6 - 10 | 11 - 15 | 16 - 20 | 21 - 25 |
| Number of Plants | 20 | 50 | 46 | 22 | 12 |
Name the modal class.
A study of the yield of 150 tomato plants, resulted in the record:
| Tomatoes per Plant | 1 - 5 | 6 - 10 | 11 - 15 | 16 - 20 | 21 - 25 |
| Number of Plants | 20 | 50 | 46 | 22 | 12 |
What is the frequency of the class preceding the modal class?
The following table give the marks scored by students in an examination:
| Marks | 0 - 5 | 5 - 10 | 10 - 15 | 15 - 20 | 20 - 25 | 25 - 30 | 30 - 35 | 35 - 40 |
| No. of students | 3 | 7 | 15 | 24 | 16 | 8 | 5 | 2 |
(i) Find the modal group
(ii) Which group has the least frequency?
The monthly salary of 10 employees in a factory are given below:
₹ 5000, ₹ 7000, ₹ 5000, ₹ 7000, ₹ 8000, ₹ 7000, ₹ 7000, ₹ 8000, ₹ 7000, ₹ 5000
Find the mean, median and mode
Find the mode of the following data.
| Class interval | 0 - 10 | 10 - 20 | 20 - 30 | 30 - 40 | 40 - 50 |
| Frequency | 7 | 13 | 14 | 5 | 11 |
The upper limit of the modal class of the given distribution is:
| Height [in cm] | Below 140 | Below 145 | Below 150 | Below 155 | Below 160 | Below 165 |
| Number of girls | 4 | 11 | 29 | 40 | 46 | 51 |
The following frequency distribution table shows the classification of the number of vehicles and the volume of petrol filled in them. To find the mode of the volume of petrol filled, complete the following activity:
| Class (Petrol filled in Liters) |
Frequency (Number of Vehicles) |
| 0.5 - 3.5 | 33 |
| 3.5 - 6.5 | 40 |
| 6.5 - 9.5 | 27 |
| 9.5 - 12.5 | 18 |
| 12.5 - 15.5 | 12 |
Activity:
From the given table,
Modal class = `square`
∴ Mode = `square + [(f_1 - f_0)/(2f_1 -f_0 - square)] xx h`
∴ Mode = `3.5 + [(40 - 33)/(2(40) - 33 - 27)] xx square`
∴ Mode = `3.5 +[7/(80 - 60)] xx 3`
∴ Mode = `square`
∴ The mode of the volume of petrol filled is `square`.
