Work out the mean of these numbers:

[tex]\[
\begin{array}{lll}
\sqrt{2} & \sqrt{18} & \sqrt{50}
\end{array}
\][/tex]

Give your answer in the form [tex]\( a \sqrt{2} \)[/tex] where [tex]\( a \)[/tex] is an integer.



Answer :

To find the mean of the numbers [tex]\(\sqrt{2}, \sqrt{18}, \sqrt{50}\)[/tex], we will first simplify each square root that we can, and then calculate the mean in the form of [tex]\(a \sqrt{2}\)[/tex].

1. Simplify [tex]\(\sqrt{18}\)[/tex]:
[tex]\[ \sqrt{18} = \sqrt{9 \times 2} = \sqrt{9} \times \sqrt{2} = 3 \sqrt{2} \][/tex]

2. Simplify [tex]\(\sqrt{50}\)[/tex]:
[tex]\[ \sqrt{50} = \sqrt{25 \times 2} = \sqrt{25} \times \sqrt{2} = 5 \sqrt{2} \][/tex]

3. List the simplified numbers:
[tex]\[ \sqrt{2}, \quad 3\sqrt{2}, \quad 5\sqrt{2} \][/tex]

4. Sum these numbers:
[tex]\[ \sqrt{2} + 3\sqrt{2} + 5\sqrt{2} \][/tex]

Combining like terms, we get:
[tex]\[ (1\sqrt{2} + 3\sqrt{2} + 5\sqrt{2}) = 9\sqrt{2} \][/tex]

5. Calculate the mean:
[tex]\[ \text{Mean} = \frac{\text{Sum of the numbers}}{\text{Number of the terms}} = \frac{9\sqrt{2}}{3} = 3\sqrt{2} \][/tex]

So, the mean of [tex]\(\sqrt{2}, \sqrt{18}, \sqrt{50}\)[/tex] is [tex]\(3\sqrt{2}\)[/tex].

Therefore, the value of [tex]\(a\)[/tex] is [tex]\(3\)[/tex].