To calculate Brianna's total bill for her interpreting services last month, we first need to convert the total time worked into quarter-hours and then multiply it by her rate of $11.25.
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Convert each session's time into total minutes:
- 5 hours and 23 minutes = \(5 \times 60 + 23 = 300 + 23 = 323\) minutes
- 4 hours and 12 minutes = \(4 \times 60 + 12 = 240 + 12 = 252\) minutes
- 5 hours and 38 minutes = \(5 \times 60 + 38 = 300 + 38 = 338\) minutes
- 1 hour and 49 minutes = \(1 \times 60 + 49 = 60 + 49 = 109\) minutes
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Calculate the total minutes for all sessions: \[ 323 + 252 + 338 + 109 = 1022 \text{ minutes} \]
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Convert total minutes into quarter-hours:
- There are 15 minutes in a quarter-hour. To find the total number of quarter-hours, we divide the total minutes by 15: \[ \frac{1022}{15} = 68.1333 \] Since she bills for any part of a quarter-hour, we round this up to the next whole number, which is 69 quarter-hours.
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Calculate the total bill: \[ 69 \times 11.25 = 776.25 \]
Thus, Brianna billed a total of $776.25 for all four sessions last month.