Final answer:
Jackie's savings account has a semiannual periodic interest rate of 3.2%, calculated by dividing the annual interest rate of 6.4% by the two periods in a year.
Step-by-step explanation:
The student is asking about the periodic interest rate for Jackie's savings account, which has an annual interest rate of 6.4% where interest is calculated on a semiannual basis. The term periodic interest rate refers to the interest rate applied to the principal during each period in which interest is computed.
Simple interest is calculated by multiplying the principal amount by the interest rate per period and the number of periods. Since the interest is calculated semiannually, we divide the annual interest rate by 2 to find the interest rate for each six-month period.
To calculate the periodic interest rate, we perform the following calculation:
Periodic Interest Rate = Annual Interest Rate / Number of Periods per Year
Periodic Interest Rate = 6.4% / 2 = 3.2% per period
Hence, Jackie's savings account has a periodic interest rate of 3.2% for each semiannual period.