Question

The arithmetic mean of the following data is 14. Find the value of k.

xi:	5	10	15	20	25
yi:	7	k	8	4	5

Answer 1

X	y	yx
5	7	35
10	k	10k
15	8	120
20	4	80
25	5	125
	N = 24 + k	\(\sum\)yx = 360 + 10k

Given,

Mean = 14

\(\frac{\sum yx}{N}=14\)

\(\frac{360+10k}{24+k}=14\)

360 + 10k = 336 + 14k

24 = 4k

k = 6

Hence, 

the value of k is 6