Hi Ivan,
You can't use .to_f on an array because that is not a method in the array class. You can only use methods on their appropriate classes, so .to_f can only be used on integers (which are objects within your array, but not the array itself).
There are a couple of ways to sum the array. The fastest way with Ruby is to do:
[your array].compact.sum
Or, in your case:
[Items].pluck('final_balance')].compact.sum
The .compact method removes nil values from the array, which is important because nil values would cause .sum to error out. The .sum method simply sums all of the numbers left in the array -- floats and ints.
If your array is truly coming out as "[nil, 4750.0, 11570.19, 3000.0]", then this means your ints and floats are not actually strings. If they were strings, it would look like [nil, "4750.0", "11570.19", "3000.0"]. This would require some additional conversion before summing, and you'd likely have to pass the array through a loop.
If that is the case, the long way might be more applicable. You would need to accumulate the value in your loop, which could be done like this:
Create a number variable called "Total" before your loop (Step 5) and set the starting value to zero. Then, within your loop, add another "Update Variable" action to add "Total" + "Final Balance Due". This will accumulate as it iterates through each item in the loop.
You might also have to add an if conditional to prevent adding nil values, as that would result in another error. If the values were strings, this is where would you use .to_f to convert each index of the array to the floats before adding.
Hope this helps!
