LAB 7.1 Working with One-Dimensional ArraysRetrieve program testscore.cpp from the Lab 7 folder. The code is as follows: // This program will read in a group of test scores (positive integers from 1 to 100)// from the keyboard and then calculate and output the average score// as well as the highest and lowest score. There will be a maximum of 100 scores.// PLACE YOUR NAME HERE#include <iostream>using namespace std;typedef int GradeType[100]; // declares a new data type:// an integer array of 100 elementsfloat findAverage (const GradeType, int); // finds average of all gradesint findHighest (const GradeType, int); // finds highest of all gradesint findLowest (const GradeType, int); // finds lowest of all gradesint main(){GradeType grades; // the array holding the grades.int numberOfGrades; // the number of grades read.int pos; // index to the array.float avgOfGrades; // contains the average of the grades.int highestGrade; // contains the highest grade.int lowestGrade; // contains the lowest grade.// Read in the values into the arraypos = 0;cout << "Please input a grade from 1 to 100, (or -99 to stop)" << endl;continues124 LESSON SET 7 Arrayscin >> grades[pos];while (grades[pos] != -99){// Fill in the code to read the grades}numberOfGrades = ; // Fill blank with appropriate identifier// call to the function to find averageavgOfGrades = findAverage(grades, numberOfGrades);cout << endl << "The average of all the grades is " << avgOfGrades << endl;// Fill in the call to the function that calculates highest gradecout << endl << "The highest grade is " << highestGrade << endl;// Fill in the call to the function that calculates lowest grade// Fill in code to write the lowest to the screenreturn 0;}//********************************************************************************// findAverage//// task: This function receives an array of integers and its size.// It finds and returns the average of the numbers in the array// data in: array of floating point numbers// data returned: average of the numbers in the array////********************************************************************************float findAverage (const GradeType array, int size){float sum = 0; // holds the sum of all the numbersfor (int pos = 0; pos < size; pos++)sum = sum + array[pos];return (sum / size); //returns the average}Lesson 7A 125//****************************************************************************// findHighest//// task: This function receives an array of integers and its size.// It finds and returns the highest value of the numbers in the array// data in: array of floating point numbers// data returned: highest value of the numbers in the array////****************************************************************************int findHighest (const GradeType array, int size){/ Fill in the code for this function}//****************************************************************************// findLowest//// task: This function receives an array of integers and its size.// It finds and returns the lowest value of the numbers in the array// data in: array of floating point numbers// data returned: lowest value of the numbers in the array////****************************************************************************int findLowest (const GradeType array, int size){// Fill in the code for this function}Exercise  1: Complete this program as directed.Exercise 2: Run the program with the following data: 90 45 73 62 -99and record the output here:Exercise 3: Modify your program from Exercise 1 so that it reads the informa-tion from the gradfile.txt file, reading until the end of file is encoun-tered. You will need to first retrieve this file from the Lab 7 folder andplace it in the same folder as your C++ source code. Run the program.