Program Description This program will calculate the average of 10 positive integers. The program will ask the user to 10 integers. If any of the values entered is negative, a message will be displayed asking the user to enter a value greater than 0. The program will use a loop to input the data.

Analysis

I will use sequential, selection and repetition programming statements. I will define two integer numbers: count, value and sum. count will store how many times values are entered. value will store the input. Sum will store the sum of all 10 integers. I will define one double number: avg. avg will store the average of the ten positive integers input.

The sum will be calculated by this formula: sum = sum + value

For example, if the first value entered was 4 and second was 10: sum = sum + value = 0 + 4 sum = 4 + 10 = 14

Values and sum can be input and calculated within a repetition loop:

while count <10

Input value sum = sum + value

End while

Avg can be calculated by:

avg = value/count

A selection statement can be used inside the loop to make sure the input value is positive.

If value >= 0 then

count = count + 1

Else

input value

End If

Test Plan

To verify this program is working properly the input values could be used for testing:

Test Case 1. Input: value=1 value=1 value=1 value=0 value=1 value=2 value=0 value=1 value=3 value=2 Expected Output: Average = 1.2

Test Case 2. Input: value=100 value=100 value=100 value=100 value=100 value=200 value=200 value=200 value=200 value=200 Expected output: Average = 150.0

Test Case 3. Input: value=100 value=100 value=100 value=100 value=-100 value = 100 value=200 value=200 value=200 value=200 Expected Output: Input a positive value average is 140.0

C Code

The following is the C Code that will compile in execute in the online compilers.

// C code

// This program will calculate the sum of 10 positive integers.

// Developer: Faculty CMIS102

// Date: Jan 31, XXXX

#include

int main ()

{

/* variable definition: */

int count, value, sum;

double avg;

/* Initialize */

count = 0;

sum = 0; avg = 0.0;

// Loop through to input values

while (count < 10)

{

printf("Enter a positive Integer ");

scanf("%d", &value);

if (value >= 0) {

sum = sum + value;

count = count + 1;

}

else {

printf("Value must be positive ");

}

}

// Calculate avg. Need to type cast since two integers will yield an integer

avg = (double) sum/count;

printf("average is %lf " , avg );

return 0;

}

1. Demonstrate you successfully followed the steps in this lab by preparing screen captures of you running the lab as specified in the Instructions above.

2. Change the code to average 20 integers as opposed to 10. Support your experimentation with screen captures of executing the new code.

3. Prepare a new test table with at least 3 distinct test cases listing input and expected output for the new code you created averaging 20 integers.

4. What happens if you entered a value other than an integer? (For example a float or even a string). Support your experimentation with screen captures of executing the code.

5. Modify the code to allow the user to enter any number of positive integers and calculate the average. In other words, the user could enter any number of positive integers. (Hint: You can prompt the user for how many they want to enter. Or; you could use a sentinel value to trigger when the user has completed entering values). Prepare a new test table with at least 3 distinct test cases listing input and expected output for the code you created. Support your experimentation with screen captures of executing the new code.