Question
Construct a frequency polygon without using a histogram for the following frequency distribution :
| Class Interval | 10-20 | 20-40 | 40-60 | 60-80 | 80-100 |
| Frequency | 9 | 17 | 15 | 20 | 14 |
✓
Answer
Steps:
1. Find class mark by calculating the average of the class interval.
2. On the $x$-axis, take $1 \mathrm{~cm}$ as 5 units and plot class interval.
3. On the $y$-axis, take $1 \mathrm{~cm}$ as 5 units and plot frequency.
4. plot the points on the graph. $(15,9),(30,17),(50,15),(70,20),(90,14)$.
5. Mark two more midpoints of zero frequency on $x$-axis at the start and at the end .
6. Now connect the points using staright lines.
1. Find class mark by calculating the average of the class interval.
2. On the $x$-axis, take $1 \mathrm{~cm}$ as 5 units and plot class interval.
3. On the $y$-axis, take $1 \mathrm{~cm}$ as 5 units and plot frequency.
4. plot the points on the graph. $(15,9),(30,17),(50,15),(70,20),(90,14)$.
5. Mark two more midpoints of zero frequency on $x$-axis at the start and at the end .
6. Now connect the points using staright lines.
| Class Interval | Class mark | Frequency |
| 10-20 | $ =\frac{10+20}{2}=15 $ | 9 |
| 20-40 | $ =\frac{20+40}{2}=30 $ | 17 |
| 40-60 | $ =\frac{40+60}{2}=50 $ | 15 |
| 60-80 | $ =\frac{60+80}{2}=70 $ | 20 |
| 80-100 | $ =\frac{80+100}{2}=90 $ | 14 |
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
An Aero plane travelled a distance of $400\ km$ at an average speed of $x\ km/hr. $ On the return journey, the speed was increased by $40\ km/hr.$ Write down an expression for the time taken for:
(1) the onward journey;
(2) the return journey.
If the return journey took 30 minutes less than the onward journey, write down an equation in x and find its value.
→(1) the onward journey;
(2) the return journey.
If the return journey took 30 minutes less than the onward journey, write down an equation in x and find its value.
Mr. Mehra sends his servant to the market to buy oranges worth $Rs.15.$ The servant having eaten three oranges on the way. Mr. Mehra pays $Rs.25$ paise per orange more than the market price.
Taking $x$ to be the number of oranges which Mr. Mehra receives, form a quadratic equation in $x.$ Hence, find the value of $x.$
→Taking $x$ to be the number of oranges which Mr. Mehra receives, form a quadratic equation in $x.$ Hence, find the value of $x.$
Construct a circle, inscribing an equilateral triangle with side 5.6 cm.
In Δ PQR, bisectors of ∠ PQR and ∠ PRQ meet at I. Prove that I is equidistant from the three sides of the triangle , and PI bisects ∠ QPR .
Two-person standing on the same side of a tower in a straight line with it measures the angle of elevation of the top of the tower as 25° and 50° respectively. If the height of the tower is 70 m find the distance between the two-person.
Find the area enclosed between two concentric circles, if their radii are $6$ cm and $13$ cm respectively.
→Equilateral triangles are drawn on the sides of a right angled triangle. Show that the area of the triangle on the hypotenuse is equal to the sum of the areas of triangles on the other two sides.
The first term of an A.P. is 5, the last term is 45 and the sum is 400. Find the number of terms and the common difference.
Gayathri wants to have a monthly income of Rs 500.For this she purchased Rs 75 shares of 'V.G.Electronics' paying 20% dividend. How many shares did Gayathri purchased and what is her investment if the market price of the share is Rs 62.50?
A hollow sphere of internal and external diameter 4 cm and 8 cm respectively is melted into acone of base diameter 8 cm. Find the height of the cone.