JAMB - Mathematics (2022 - No. 5)
If the mean of 2, 5, (x+1), (x+2), 7 and 9 is 6. Find the median
5.5
5
6.5
6
คำอธิบาย
Firstly; solving for x
6 = \(\frac{2 + 5 + x+1 + x+2 + 7 + 9}{6}\)
cross multiply to have:
6 * 6 = 2 + 5 + x+1 + x+2 + 7 + 9
36 = 2x + 26
36 - 26 = 2x
10 = 2x
x = 5
Median = \(\frac{7+6}{2}\)
→ 6.5