Being new to learning PHP I am having trouble with understanding how to select/echo/extract a value from array result a API script returns.

Using the standard:

echo "<pre>";
print_r($ups_rates->rates);
echo "</pre>";

The results returned look like this:

Array
(
    [0] => Array
        (
            [code] => 03
            [cost] => 19.58
            [desc] => UPS Ground
        )

    [1] => Array
        (
            [code] => 12
            [cost] => 41.69
            [desc] => UPS 3 Day Select
        )

    [2] => Array
        (
            [code] => 02
            [cost] => 59.90
            [desc] => UPS 2nd Day Air
        )
)

If I am only needing to work with the values of the first array result: Code 3, 19.58, UPS Ground --- what is the correct way to echo one or more of those values?

I thought:

$test = $ups_rates[0][cost];
echo $test;

This is obviously wrong and my lack of understanding the array results isn't improving, can someone please show me how I would echo an individual value of the returned array and/or assign it to a variable to echo the normal way?