Express $0.001$ neighbourhood of $3$ in interval form.
Answer
Comparing $0.001$ neighbourhood of $3$ with $\delta$ neighbourhood of $a,$
we get a $=3$ and $\delta=0.001$.
Interval Form : $(a-\delta, a+\delta)$,Putting $a =3$ and $\delta=0.001$
$0.001$ neighbourhood of $3=(3-0.001,3+0.001)=(2.999,3.001)$
The percentage change in the value of a variable associates with any item four the given $($current$)$ period compared to its value in a fixed $($base$)$ period is called an Index Number.