A manager was assigned the task of investigating the error in payments for routine purchases made by the purchasing department. The manager randomly selected 12 payments, investigated them thoroughly, and determined the payment error for each of these payments. The payment error was defined as the difference between the amount paid and what should have been paid. The payment errors determined for these selected payments were as follows: $17 $25 $14 -$10 $20 $40 $35 $30 $28 $22 $15 $16 (1) Determine the (two-sided) 95% confidence interval for the population mean payment error, and type the value of the upper bound in your (two-sided) confidence interval. (You don’t need to type the value of the lower bound in the confidence interval). Please keep your answer with 2 decimal places.