Percentile no. $$$25$$$ of $$$35$$$, $$$28$$$, $$$43$$$, $$$32$$$

Find the percentile no. $$$25$$$ of $$$35$$$, $$$28$$$, $$$43$$$, $$$32$$$.

The percentile no. $$$p$$$ is a value such that at least $$$p$$$ percent of the observations is less than or equal to this value and at least $$$100 - p$$$ percent of the observations is greater than or equal to this value.

The first step is to sort the values.

The sorted values are $$$28$$$, $$$32$$$, $$$35$$$, $$$43$$$.

Since there are $$$4$$$ values, then $$$n = 4$$$.

Now, calculate the index: $$$i = \frac{p}{100} n = \frac{25}{100} \cdot 4 = 1$$$.

Since the index $$$i$$$ is an integer, the percentile no. $$$25$$$ is the average of the values at the positions $$$i$$$ and $$$i + 1$$$.

The value at the position $$$i = 1$$$ is $$$28$$$; the value at the position $$$i + 1 = 2$$$ is $$$32$$$.

Their average is the percentile: $$$\frac{28 + 32}{2} = 30$$$.

The percentile no. $$$25$$$A is $$$30$$$A.