11. Kara's credit card had a balance of $209.53 on July
1. On July 8, she made a payment of $50. On July
16, she made a charge of $20. On July 24, she
made another charge of $35 and did not use the
credit card the rest of the month. What was her
average daily balance?
$159.53
$179.53
$214.53
$190.18
$190.78

When we calculate the average daily balance, we total the balance from each day in the billing cycle and divide the total by the number of days in the cycle. Here the billing cycle is given for July that has 31 days.

Lets calculate each days amount.

Opening balance from 1st July to 7th July = $209.53

So, it is a total of 7 days; amount is [tex]209.53\times7=1466.71[/tex]

On 8th July a payment of $50 is made making the amount

[tex]209.53-50=159.53[/tex]

So, from 8th July to 15th July (8 days), the balance was $159.53 making a total of [tex]159.53\times8=1276.24[/tex] dollars

On 16th July a charge of $20 was added, so from 16th July to 23 July (8 days), the amount became = [tex](159.53+20)\times8=1436.24[/tex] dollars

On 24th July additional charge of $35 was added and the period it remained same was till 31st July, making it 8 days.

So, amount is = [tex]214.53\times8=1716.24[/tex] dollars

Now adding all the charges we get;

[tex]1466.71+1276.24+1436.24+1716.24= 5895.43[/tex] dollars

Now we will divide this by 31 days to get the average daily balance.

[tex]\frac{5895.43}{31}=190.175[/tex] ≈ $190.18