To find the total cost including tax and tip, we can break the problem down into a few steps:
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Calculate the Sales Tax: \[ \text{Sales Tax} = \text{Cost} \times \text{Tax Rate} \] \[ \text{Sales Tax} = 105.79 \times 0.09 = 9.4781 \approx 9.48 \text{ (rounded to two decimal places)} \]
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Calculate the Total Cost including Tax: \[ \text{Total Cost with Tax} = \text{Cost} + \text{Sales Tax} \] \[ \text{Total Cost with Tax} = 105.79 + 9.48 = 115.27 \]
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Calculate the Tip (based on pre-tax amount): \[ \text{Tip} = \text{Cost} \times \text{Tip Rate} \] \[ \text{Tip} = 105.79 \times 0.20 = 21.158 \approx 21.16 \text{ (rounded to two decimal places)} \]
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Calculate the Total Amount including Tip: \[ \text{Total Amount} = \text{Total Cost with Tax} + \text{Tip} \] \[ \text{Total Amount} = 115.27 + 21.16 = 136.43 \]
Thus, the total amount Jesse will pay, including tax and tip, is $136.43.