Final answer:
To calculate the total price including tax, convert the tax rate to a decimal, multiply it by the item's price, and add the result to the original price. If the phone's price is $39, a 5% tax would add $1.95, totaling $40.95.
Step-by-step explanation:
To find the total price including sales tax of a new phone, you must first have the initial price of the phone, which seems to be missing in the question. Assuming the price of the phone is provided as $39, which seems to be a typo in the original question, we would follow these steps:
Convert the sales tax rate from a percent to a decimal by dividing by 100 (5% becomes 0.05).
Multiply the price of the phone by the decimal sales tax rate to find the amount of sales tax. For a $39 phone, the calculation would be $39 × 0.05 = $1.95 in sales tax.
Add the sales tax to the original price to find the total cost. So, $39 + $1.95 = $40.95.
Remember to always round your sales tax to the nearest cent for the total price. In this example, the sales tax is already rounded to the cent, so there's no need for further adjustment in the total cost.