Question 28 (OR 1 st question)

The median of the following data is 525. Find the values of x and y if the total frequency is 100.

Class Interval

Frequency

0 – 100

2

100 – 200

5

200 – 300

x

300 – 400

12

400 – 500

17

500 – 600

20

600 – 700

y

700 – 800

9

800 – 900

7

900 – 100

4

The median of the data is 525. Find x and y if total frequency is 100

Question 28 (Or 1st) - CBSE Class 10 Sample Paper for 2019 Boards - Part 2
Question 28 (Or 1st) - CBSE Class 10 Sample Paper for 2019 Boards - Part 3
Question 28 (Or 1st) - CBSE Class 10 Sample Paper for 2019 Boards - Part 4
Question 28 (Or 1st) - CBSE Class 10 Sample Paper for 2019 Boards - Part 5


Transcript

Question 28 (OR 1st question) The median of the following data is 525. Find the values of x and y if the total frequency is 100. Given that total frequency is 100 So, Sum of frequency = 100 2 + 5 + x + 12 + 17 + 17 + 20 + y + 8 + 7 + 4 = 100 76 + x + y = 100 x + y = 100 – 76 x + y = 24 Now, to find values of x and y, We first find median Since Median is 525 500 – 600 is the median class Median = l + (𝑛/2 − 𝑐𝑓)/𝑓 × h Where l = lower limit of median class = 500 h = class-interval = 100 − 0 = 100 n = ∑▒𝑓𝑖 = 100 cf = cumulative frequency of the class before median class = 36 + x f = frequency of the median class = 20 Now, Median = l + (𝑛/2 −𝑐𝑓)/𝑓 × h 525 = 500 + (100/2 − (36 + 𝑥))/20 × 100 525 – 500 = (50 − (36 + 𝑥))/20 × 100 25 = (14 − 𝑥)/20 × 100 25 = (14 – x) × 5 25 = 70 – 5x 5x = 70 – 25 5x = 45 x = 45/9 x = 5 Now, from (1) x + y = 24 Putting x = 5 5 + y = 24 y = 24 – 5 y = 19 Thus, x = 5, y = 19

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.