Answer to Question #209267 in C for jason

Question

Declare an array to store up to 10 integer percentage values.

Ask the user to input 10 percentages (range 0 – 100). Verify that the input is valid, before storing it in the array. Note that only valid (0 – 100) percentages may be stored. If the user enters an invalid percentage, display an error message and do not store or process the invalid value.

  

Once all 10 valid percentages are entered, calculate the average percentage and display it.  

Calculate and display the highest and lowest percentage.

Then display all percentages that are equal to or more than the average.

  

Lastly, display all 10 values entered by the user together with their letter grade values.

  

  

  

Plan, Code and use function(s) to:

• Return a letter grade from a test percentage.
• Calculate and return the average percentage.
• Calculate and return the highest percentage.
• Calculate and return the lowest percentage.

Answer 1

#include<stdio.h>
#include<stdlib.h>


#define totalPercentages 10


char calculateLetterGrade(int percentage);
float calculateAveragePercentage(int percentages[]);
int calculateHighestPercentage(int percentages[]);
int calculateLowestPercentage(int percentages[]);


//The start point of the program
int main(){
	//Declare an array to store up to 10 integer percentage values.
	int percentages[totalPercentages];
	int percentage=0;
	int i=0;
	float average;
	for(i=0;i<totalPercentages;i++){
		percentage=-1;
		while(percentage<0 || percentage>100){
			printf("Enter test percentage %d [0-100]: ",(i+1));
			scanf("%d",&percentage);
			if(percentage<0 || percentage>100){
				printf("\nInvalid percentage.Try again.\n\n");
			}
		}
		percentages[i]=percentage;
	}
	average=calculateAveragePercentage(percentages);
	//Once all 10 valid percentages are entered, calculate the average percentage and display it.  
	printf("\nThe average percentage: %.2f\n",average);
	//Calculate and display the highest and lowest percentage.
	printf("The highest percentage: %d\n",calculateHighestPercentage(percentages));
	printf("The lowest percentage: %d\n",calculateLowestPercentage(percentages));
	//Then display all percentages that are equal to or more than the average.
	printf("\n\nAll percentages that are equal to or more than the average:\n");
	for(i=0;i<totalPercentages;i++){
		if(percentages[i]>=average){
			printf("%d ",percentages[i]);
		}
	}
	//Lastly, display all 10 values entered by the user together with their letter grade values.
	printf("\n\nTest percentage\t\tLetter grade\n");
	for(i=0;i<totalPercentages;i++){
		printf("%d\t\t\t%c\n",percentages[i],calculateLetterGrade(percentages[i]));
	}
	getchar();
	getchar();
	return 0;
}


//Return a letter grade from a test percentage.
char calculateLetterGrade(int percentage){
	//80 to 100 A
	if(percentage>=80 && percentage<=100){
		return 'A';
	}
	//70 to 79 B
	if(percentage>=70 && percentage<=79){
		return 'B';
	}
	//60 to 69 C
	if(percentage>=60 && percentage<=69){
		return 'C';
	}
	//50 to 59 D
	if(percentage>=50 && percentage<=59){
		return 'D';
	}
	//0-49 F
	return 'F';
}
//Calculate and return the average percentage.
float calculateAveragePercentage(int percentages[]){
	int i,sum=0;
	for(i=0;i<totalPercentages;i++){
		sum+=percentages[i];
	}
	return sum/totalPercentages;
}


//Calculate and return the highest percentage.
int calculateHighestPercentage(int percentages[]){
	int highestPercentage=percentages[0];
	int i;
	for(i=1;i<totalPercentages;i++){
		if(percentages[i]>highestPercentage){
			highestPercentage=percentages[i];
		}
	}
	return highestPercentage;
}
//Calculate and return the lowest percentage.
int calculateLowestPercentage(int percentages[]){
	int lowestPercentage=percentages[0];
	int i;
	for(i=1;i<totalPercentages;i++){
		if(percentages[i]<lowestPercentage){
			lowestPercentage=percentages[i];
		}
	}
	return lowestPercentage;
}