the total cost of an item including sales tax is directly proportional to its price. if the total cost of a…

Explanation:

Step1: Find the tax rate

The cost of the item is $25 and the total cost is $25.75. So the tax amount is $25.75 - 25=0.75$. The tax - rate $r$ is calculated by $\frac{\text{Tax amount}}{\text{Cost of item}}$, so $r=\frac{0.75}{25}=0.03$ or 3%.

Step2: Calculate the total cost of a $60 item

The tax on a $60 item is $60\times0.03 = 1.8$. The total cost $C$ of a $60 item is the sum of the item cost and the tax, so $C=60 + 1.8=61.8$.

Answer:

$61.80$