Question

13. Find the value of p, if the mean of the following data is 20
15
19
20 + P
23
f
2.
3
4.
5р
6​

Answer 1

Answer:

x f fx

15 2 30

17 3 51

19 4 76

20+P 5P 100P + 5P2

23 6 138

N = 5P + 15 ∑fx = 295 + 100P + 5P2

Given

⇒ Mean = 20

⇒∑fxN=20

⇒295+100P+5P25P+15=20

⇒ 295 + 100P + 5P 2 = 20(5P + 15)

⇒ 295 + 100P + 5P 2 = 100P + 300

⇒ 100P - 100P + 5P 2 = 300 - 295

⇒ 5P2 = 5

⇒ P2 = 1

⇒ P = 1