Question

We are designing a program that must do the following:

Read 3 integers from a file called "data.txt"
Sum the integers
Compute the mean of the integers
Output the mean to a file called "mean.txt".
We are required to select functions from the library provided below to complete our program. Inside of the main () function, fill in the correct C statements to satisfy the four requirements listed above. You must fill in all the lines labeled with "statement x", where x is 2, 3, 4, 5, or 6. The first statement has been completed for you.
// These are the library functions that we must invoke!
// Precondition: The input file must already be open.
int read_integer (FILE *infile)
{
int number = 0;
fscanf (infile, "%d", &number);
return number;
}

int calculate_sum (int number1, int number2, int number3)

{
int sum = 0;
sum = number1 + number2 + number3;
return sum;
}

double calculate_mean (int sum, int number)
{
double mean = 0.0;
mean = ((double) sum) / number;
return mean;
}
// Precondition: The input file must already be open.
void print_double (FILE *outfile, double number)
{
fprintf (outfile, "%0.2lf\\", number);
}
// Fill in the appropriate statements for main ().
#include
int main (void)
{
int n1 = 0, n2 = 0, n3 = 0, sum = 0;
double average = 0.0;
FILE *infile = NULL, *outfile = NULL;
// We will not check to see if files were opened successfully; assume they are
infile = fopen ("data.txt", "r");
outfile = fopen ("mean.txt", "w");
______n1 = read_integer (infile)_________________________ // statement 1
_________________________________________________________ // statement 2 (2 pts)
_________________________________________________________ // statement 3 (2
pts)
_________________________________________________________ // statement 4 (2 pts)
_________________________________________________________ // statement 5 (2 pts)
_________________________________________________________ // statement 6 (2
pts)
fclose (infile);
fclose (outfile);
return 0;
}

Answer 1

Data input

1. number1 = read_integer (infile) //read number1

2. number2 = read_integer (infile); //read number2

3. number3 = read_integer (infile); //read number3

Data treatment

4. values = calculate_sum (int number1, int number2, int number3);

5. average = calculate_mean (int values, int number);

Output values

6. print_double (FILE *outfile, double average);