Question

If the average of 16, 14, x, 23, 20 is 18, find the value of x

Answer 1

Given:

✰ Average or mean = 18

To find:

➳ Value of x

Method :

$\sf{mean = \dfrac{sum \: of \: all \: observations}{total \: number \: of \: observations} } \\ \\ \implies \sf{ 18 = \frac{16 + 14 + x + 23 + 20}{5} } \\ \\ \implies \sf{18 = \frac{73 + x}{5} } \\ \\ \implies \sf{18 \times 5 = 73 + x} \\ \\ \implies \sf{73 + x = 90} \\ \\ \implies \sf{x = 90 - 73} \\ \\ \implies \boxed{ \sf{x = 17}}$

Therefore Value of x = 17

Additional information:

• For finding mean of ungrouped data, there is only 1 method which is given above

• There are 3 methods for finding mean of grouped data

1. Direct method
2. Assumed mean method
3. Step deviation method

• Grouped data means the data is represented in a table.

• Ungrouped data means the data is arranged in a single line