if your have height and weight of your family memberas a list in two variables
like weight=[25,46,81,70] and height=[180,140,160,155] in order then your
cannot perform operations like calculating BMI=weight/(height)**2 or any other because python
list contains different data types and numerical operations is impossible. And,
also in python list the operation of bmi cannot be cannot calculated by using
indexed list of weight and similar height. So for this, numpy array is the
solution where your convert python list to numpy array and can do literaaly
anything that python list cannot