If mean of the numbers $2, (2p+2), 7, 13, 17, 4$ and $(p-1)$ is 8, then find their median.
Answer & explanation
Correct answer: option 3
We're given that the mean of these numbers is 8, which means:
\(\frac{(2 + 2p + 2 + 7 + 13 + 17 + 4 + p - 1) }{7}\) = 8
4p + 46 = 56
4p = 10
p = 2.5
So, all numbers are,
(2 , 2 × 2.5 , 2 , 7 , 13 , 17 , 4 , 2.5 - 1)
= (2 , 5 , 2 , 7 , 13 , 17 , 4 , 1.5)
Now, arrange these numbers in ascending order:
1.5 , 2 , 4, 7, 7, 13, 17
In this case, there are 7 numbers ( odd number )
So, Median = [\(\frac{( n + 1 )}{2}\)]th term
= [\(\frac{( 7 + 1 )}{2}\)]th term
= 4th term
So, the median of the given numbers is 7.