Final answer:
To find the total amount Alex earned for the summer, calculate his commission by multiplying his total sales by his commission rate of 18 1/4%. The commission can be found by converting the commission rate to a decimal and multiplying it by the total sales. The answer is $2,827.50.
Step-by-step explanation:
To calculate the total amount Alex earned for the summer, we need to calculate his commission first. Alex sold 38 ads at a total sales of $15,500, so his commission is 18 1/4% of $15,500.
To find the commission, we can convert 18 1/4% into a decimal by dividing it by 100, which gives us 0.1825. Then, we can multiply 0.1825 by $15,500 to find Alex's commission.
Commission = 0.1825 * $15,500 = $2,827.50
Therefore, the total amount Alex earned for the summer is $2,827.50.