[hannehomuth]

Hey this is realy simple. But you have to learn to work with for loops or stuff like that. I will give you a little example.

To calculate the sum you have to write code like this.

Code:

double sum = 0;
for(int i=0;i<prices.length;i++)
{
  sum = sum + prices[i];
}

This code will go through the whole array and adds each value in the array to the variable sum.

In other Words it does exactly this

Code:

double sum = prices[0] + prices[1] + prices[2] + prices[3] + prices[4] + prices[5] + prices[6] +
prices[7] + prices[8] + prices[9] + prices[10] + prices[11] + prices[12] + prices[13] +
prices[14]+ prices[15] + prices[16] + prices[17] + prices[18] + prices[19];

only cooler.

And if you wanna know how many are under 5

Code:

int howManyUnderFive = 0;
for(int i=0;i<prices.length;i++)
if(prices[i] < 5)
howManyUnderFive++;

Learn to use loops, you will not be able to do more stuff if you dont learn that. Its nesseary for everything, but its easy to understand. I hope it helps you