Program is in C++ . Write a function named averageValueInFile that accepts a file name as a parameter and reads that file, assumed to be full of real numbers, and returns the average (mean) of the numbers in that file. The parameter, filename, gives the name of a file that contains a list of real numbers, one per line. You may assume that the file exists and follows the proper format. For example, if a file named input.txt contains the following numbers

1.5 2.75 9.0 -3.25 0.0 6.5 

Then the call of averageValueInFile("input.txt"); should return 2.75.

You may assume that the input file exists and is in the proper format. If the file does not contain any input values, return 0.0.

Constraints: Your solution should read the file only once, not make multiple passes over the file data.