Creating a program using Java PL that mimics a calculator

SOURCE: I am java beginner and I want a help in writing a

the best thing to do here is to separate the steps for calculating the variance into different functions. To compute the variance the first thing to do is to compute the mean or the average of the numbers in the array. so your first function will loop through each of the numbers and divide it by the length of your array. the output is the returned. The next thing to do is create another function for the variance. loop through each of the numbers again and subtract to each number the mean. square the value then add to the previous. so that means you have another variable that starts from zero and just adds the answer. after that divide it by the length of the array again and what you are going to get is the value for the variance.