def convert_usd_to_aud (amount, rate = 0.75):
    return amount/rate

def convert_and_sum_list(usd_list, rate = 0.75):
    total = 0
    for amount in usd_list:
        total += convert_usd_to_aud (rate = rate)
    return (total)
print(convert_and_sum_list([1,3]))


def convert_and_sum_list_kwargs(usd_list, **kwargs):
    total = 0
    for amount in usd_list:
        total += convert_usd_to_aud(amount, **kwargs)
    return total
print(convert_and_sum_list_kwargs([1, 3], rate=0.8))