Write a program that reads in numbers (of type double) from a file, stores them in an array, and then calculates the mean, variance, and standard deviation.
Your program should solve the problem by using the following methods implemented in a class..named Calculate.java
This class should implement the following methods:
1. One method to count the number of data numbers in the input file. This method should:
o be public and static
o be named countData
o accept a String representing the filename
o return an integer that represents the number of numbers in the data file
2. One method to read the numbers and the data file. This method should:
o be public and static
o be named readData
o accept a String representing the filename, and a parameter for an array of type double
3. One method to calculate the mean value
This method should:
o be public and static
o be named calMean
o accept an array of type double
o return the calculated mean as a number of type double
4. One method to calculate the variance
This method should:
o be public and static
o be named calVariance
o accept an array of type double and the calculated mean value as a double
o return the calculated variance as a number of type double