Question

If the mean of the following data is 15, find p.
x:
5
10
15
20
25
f:
6
p
6
10
5

Answer 1

ARITHMETIC MEAN OR MEAN OR AVERAGE :  

The arithmetic mean of a set of observations is obtained by dividing the sum of the values of all observations by the total number of observations .

Mean = Sum of all the observations / Total number of observations .

MEAN = Σfixi / Σfi

[‘Σ’ Sigma means ‘summation’ ]

FREQUENCY DISTRIBUTION TABLE IS IN THE ATTACHMENT  

From the table : Σfixi = 445 + 10p , Σfi = 27 + p

MEAN = Σfixi / Σfi  

Given : Mean = 15

15   = (445 + 10p) / (27 + p)

15 × (27 + p)  = 445 + 10p

405 + 15p = 445 + 10p

15p - 10p = 445 - 405  

5p = 40

p = 40/5 = 8  

p = 8  

Hence, the value of ‘p’ is 8.

HOPE THIS ANSWER WILL HELP YOU….

Answer 2

Answer:

Step-by-step explanation:

Given : Mean = 15

15   = (445 + 10p) / (27 + p)

15 × (27 + p)  = 445 + 10p

405 + 15p = 445 + 10p

15p - 10p = 445 - 405  

5p = 40

p = 40/5 = 8  

p = 8