Question

The diameter (in $\text{cm}$) of a wire as measured by the screw gauge is found to be $2.620,2.625,2.628$ and $2.626$. The mean value of the diameter is

• A. $2.62\text{cm}$
• B. $2.625\text{cm}$
• C. $2.624\text{cm}$
• D. $2.6248\text{cm}$

Answer 1

The correct option is B $2.625\text{cm}$

Arithmetic mean,
$a_{mean}=\frac{a_1+a_2+a_3+.....+a_n}{n}$
$\Rightarrow a_{mean}=\frac{2.620+2.625+2.628+2.626}{4}$
$\Rightarrow a_{mean}=2.62475\text{cm}$
On rounding off to correct decimal places, we get, $a_{mean}=2.625\text{cm}$