a. To find the tip amount using scaling, Josea needs to multiply the total bill by 15%, or 0.15. This can be represented as a fraction by writing it as 15/100. It can be represented as a decimal by simply converting the percentage to a decimal, which is 0.15. Both representations are equally valid for solving this problem, but using the decimal may be easier since it involves fewer steps.
b. To find out how much Josea should leave for the tip, we can multiply the total bill by the tip percentage:
Tip amount = 0.15 x $38
Tip amount = $5.70
Therefore, Josea should leave a tip of $5.70.
c. If Josea decides to leave a 20% tip instead, we can use the same method as before:
Tip amount = 0.20 x $38
Tip amount = $7.60
Therefore, if Josea wants to leave a 20% tip, she should leave $7.60.
(If this doesn’t seem right to you make sure you comment!)