How to add two array key values and return as a new key in PHP

I have an array($data) like this.

Array
(
    [0] => Array
        (
            [PID] => 1
            [USER_NAME] => JOHN
            [JOINED_DATE] => 2022-01-31
            [JOINED_VALUE] => 23233.80
            [TOPUP_AMOUNT] => 58000.00
            [TOTAL_EXPENSES] => 3114.41
        )
.....

I need to get a new key called TOTAL_BALANCE and it should get as follows,

TOTAL_BALANCE=JOINED_VALUE+TOPUP_AMOUNT+TOTAL_EXPENSES

Final output should look as follows,

Array
    (
        [0] => Array
            (
                [PID] => 1
                [USER_NAME] => JOHN
                [JOINED_DATE] => 2022-01-31
                [JOINED_VALUE] => 23233.80
                [TOPUP_AMOUNT] => 58000.00
                [TOTAL_EXPENSES] => 3114.41
                [TOTAL_BALANCE] => 78119.39
            )
    .....

Can someone help me to achieve this?

Here is my try, but I am not sure this is correct or not.

$r = [];
$keys = array_keys($key1+$key2);
foreach($keys as $v){
  ??
}

>Solution :

Do it like this:

$data = Array(
    0 => Array(
        'PID' => 1,
        'USER_NAME' => 'JOHN',
        'JOINED_DATE' => '2022-01-31',
        'JOINED_VALUE' => 23233.80,
        'TOPUP_AMOUNT' => 58000.00,
        'TOTAL_EXPENSES' => 3114.41,
    ),
    1 => Array(
        'PID' => 2,
        'USER_NAME' => 'JOHN_2',
        'JOINED_DATE' => '2022-01-31',
        'JOINED_VALUE' => 1234.80,
        'TOPUP_AMOUNT' => 1000.00,
        'TOTAL_EXPENSES' => 3114.41,
    )
);

foreach($data as &$value){
    // Sum and store
    $value['TOTAL_BALANCE'] = $value['JOINED_VALUE'] + $value['TOPUP_AMOUNT'] + $value['TOTAL_EXPENSES'];
}

print_r($data);

Output:

Array
(
    [0] => Array
        (
            [PID] => 1
            [USER_NAME] => JOHN
            [JOINED_DATE] => 2022-01-31
            [JOINED_VALUE] => 23233.8
            [TOPUP_AMOUNT] => 58000
            [TOTAL_EXPENSES] => 3114.41
            [TOTAL_BALANCE] => 84348.21
        )

    [1] => Array
        (
            [PID] => 2
            [USER_NAME] => JOHN_2
            [JOINED_DATE] => 2022-01-31
            [JOINED_VALUE] => 1234.8
            [TOPUP_AMOUNT] => 1000
            [TOTAL_EXPENSES] => 3114.41
            [TOTAL_BALANCE] => 5349.21
        )

)