Suppose that the effective interest rate per interest period is 6%. Describe what the following annuity symbol (1150, 15a) 15) means. The value one interest period before the first payment of an annuity-immediate, where the first payment is for $150 and each subsequent payment is $15 more. The value at the time of the last payment of an annuity-immediate, where each payment is one less than its predecessor. The value at the time of the first payment of an annuity-immediate, where the first payment is for $15 and each subsequent payment is $150 more. The value at the time of the first payment of a perpetuity-due with payments decreasing by 1 each period. The value at the time of the first payment of a perpetuity-due with payments increasing by 1 each period