Solution:
The average daily balance is calculated below with the number of days given and the balance within that interval;
[tex]\begin{gathered} =\frac{5(200)+15(350)+10(150)}{30} \\ =\frac{1000+5250+1500}{30} \\ =\frac{7750}{30} \\ =\text{ \$258.33} \end{gathered}[/tex]
The annual percentage rate (APR) is given by 10.5%
Since 365 days are in a year, the daily percentage rate is given by;
[tex]\begin{gathered} =\frac{10.5}{365} \\ =0.02876\text{ \%} \end{gathered}[/tex]
Hence, the daily finance charge on the average daily balance is;
[tex]\begin{gathered} =\frac{0.02876}{100}\times258.33 \\ =\text{ \$0.0743} \end{gathered}[/tex]
This daily finance charge over a period of one month (30days) will therefore be;
[tex]\begin{gathered} =0.0743\times30 \\ =\text{ \$2.229} \\ \\ To\text{ the nearest hundredth,} \\ =\text{ \$2.23} \end{gathered}[/tex]
Therefore, the finance charge on the average daily balance for the credit card over 1 month period to the nearest hundredth is $2.23