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brittany435

Mar 26th, 2008 3:56 pm

Writing a program with an array that averages 10 numbers

Hello,

I am working on a small program that reads ten numbers, computes their average, and finds out how many numbers are above average. This is the set up I have so far:

#include <iostream>
using namespace std;

int main()
{
double myList[10];

myList[0] = 89
myList[1] = 56
myList[2] = 34
myList[3] = 98
myList[4] = 87
myList[5] = 94
myList[6] = 100
myList[7] = 69
myList[8] = 52
myList[9] = 73

return 0;
}

.... Now I just need to know how to use it!

Thanks for all the help!

Miyuki

Mar 26th, 2008 4:04 pm

Re: Writing a program with an array that averages 10 numbers

For average, try

double average;
average = ( myList[0] + myList[1] ... ) / 10;

A for loop is really better, but I will let you try it first.

For number above average

int i,numabove;
for ( you do this part )
if ( myList[i] > average ) numabove++

Finally output numabove

brittany435

Mar 26th, 2008 4:48 pm

Re: Writing a program with an array that averages 10 numbers

#include <iostream>
using namespace std;

int main()
{
// Declare Variables
double myList[10];
double average;

// Define Array
myList[0] = 89;
myList[1] = 56;
myList[2] = 34;
myList[3] = 98;
myList[4] = 87;
myList[5] = 94;
myList[6] = 100;
myList[7] = 69;
myList[8] = 52;
myList[9] = 73;

//calculate average
average = ( myList[0] + myList[1] + myList[2]+ myList[3]+ myList[4]+ myList[5]
+ myList[6]+ myList[7]+ myList[8]+ myList[9]) / 10;

// Display average
cout <<"The average score is " << average <<"\n\n";

//Find out how many numbers are above average
int i;
for (i = 0; i > average; i++)
int numabove;
if (myList[i]>average)
numabove++;

cout << "The numbers above average are" << numabove;

return 0;
}

This is what I have so far but I can't get the for loop wrong. I'm not initializing numabove and I'm not sure how.

Miyuki

Mar 26th, 2008 4:55 pm

Re: Writing a program with an array that averages 10 numbers

You want the for loop to count 0 to 9.

In
for (i = 0; i > average; i++)
set the middle part to i < 10

Compton11

Mar 26th, 2008 5:03 pm

Re: Writing a program with an array that averages 10 numbers

Brittany, you shouldn't declare variables within a loop...Here's what you should do:

#include <iostream>

using namespace std;



int main()

{



// Declare Variables

double myList[10];

double average;

double sum = 0;

int numabove = 0;



// Define Array

myList[0] = 89;

myList[1] = 56;

myList[2] = 34;

myList[3] = 98;

myList[4] = 87;

myList[5] = 94;

myList[6] = 100;

myList[7] = 69;

myList[8] = 52;

myList[9] = 73;



//calculate average



//Make a loops traversing all of the 10 values in the myList array 

//and add each one to a variable named sum

for (int i = 0; i < 10; i++)

      sum += myList[i];



//calculate average by getting that sum and dividing it by 10

average = (sum/10);



// Display average

cout <<"The average score is " << average <<"\n" << endl;





//Find out how many numbers are above average by using a loop



for (int i = 0; i < 10; i++)

{

    if (myList[i]>average)

          numabove++;

}



cout << "The numbers above average are: " << numabove << endl;







return 0;

}

brittany435

Mar 26th, 2008 5:14 pm

Re: Writing a program with an array that averages 10 numbers

Quote:

Originally Posted by Miyuki (Post 569791)

You want the for loop to count 0 to 9.

In
for (i = 0; i > average; i++)
set the middle part to i < 10

I was able to get that working, now I need the user to input the scores. I have it all set up, but I'm getting some crazy average.

#include <iostream>
using namespace std;

int main()
{
// Declare Variables
const int TOTAL_NUMBERS = 10;
int numbers[TOTAL_NUMBERS];
double average;

//Read all numbers
for (int i = 0; i < TOTAL_NUMBERS; i++)
{
cout << "Enter a score: ";
cin >> numbers[i];
}

//Find the average
average = ( numbers[TOTAL_NUMBERS] + numbers[TOTAL_NUMBERS]) /10;

// Display average
cout <<"The average score is " << average <<"\n\n";

return 0;
}

Compton11

Mar 26th, 2008 5:26 pm

Re: Writing a program with an array that averages 10 numbers

Brittany, you can't do cin >> number[i]..That will not read a value and store it in the array...Do something like this: ...Remember to add to my reputation!

#include <iostream>

using namespace std;



int main()

{

// Declare Variables

const int TOTAL_NUMBERS = 10;

int numbers[TOTAL_NUMBERS];

double average;

double sum = 0.0;

int num;



        //Read all numbers

        for (int i = 0; i < TOTAL_NUMBERS; i++)

        {

                cout << "Enter a score: ";

                cin >> num;

                numbers[i] = num;

                sum += numbers[i];

        }



        //Find the average

        average =  sum/10;



        // Display average

        cout <<"\nThe average score is " << average <<"\n\n";





return 0;

}

VernonDozier

Mar 26th, 2008 6:08 pm

Re: Writing a program with an array that averages 10 numbers

Quote:

Originally Posted by Compton11 (Post 569810)

Brittany, you can't do cin >> number[i]..That will not read a value and store it in the array...Do something like this: ...Remember to add to my reputation!

cin >> num;

numbers[i] = num;

cin >> numbers[i];

works fine. The way you did it works too, but involves an extra step. You don't have to read from cin into an integer, then assign that integer to the array. Reading it directly from cin into the array works too.

WaltP

Mar 26th, 2008 10:40 pm

Re: Writing a program with an array that averages 10 numbers

Quote:

Originally Posted by Compton11 (Post 569810)

Brittany, you can't do cin >> number[i]..That will not read a value and store it in the array...Do something like this: ...Remember to add to my reputation!

That is exactly how to read in a value into the array. Don't know where you get the idea it can't.

        //Find the average

        average = ( numbers[TOTAL_NUMBERS] + numbers[TOTAL_NUMBERS]) /10;

Since when is adding two numbers together then dividing by 10 giving an average?

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