Question 47

Jambmaths question: 

Calculate the standard deviation of 5, 4, 3, 2 and 1

Option A: 

$\sqrt{3}$

Option B: 

$\sqrt{6}$

Option C: 

$\sqrt{10}$

Option D: 

$\sqrt{2}$

Jamb Maths Solution: 

$\begin{align}  & \text{mean }\overline{x}=\frac{5+4+3+2+1}{5}=3 \\ & variance=\frac{{{(5-3)}^{2}}+{{(4-3)}^{2}}+{{(3-3)}^{2}}+{{(2-3)}^{2}}+{{(1-3)}^{2}}}{5} \\ & variance=\frac{4+1+0+1+4}{5}=2 \\ & standard deviation\text{ =}\sqrt{variance}=\sqrt{2} \\\end{align}$

Jamb Maths Topic: 
Year of Exam: