Acredit card had an apr of 18.78% all of last year and compounded interest daily. what was the credit card's effective interest rate last year?

20.65%

Step-by-step explanation:

Formula to calculate effective interest rate :

Effective interest rate

where r = Rate of interest = 18.78% = 0.1878

           n = number of compounding period = 365

Now put the values into formula

= 1.206534 - 1

= 0.206534

= 20.65%

Last year Effective interest rate was 20.65%.