You fill your car with 15 gallons of gas at a cost of $45. Using fractional notation, how do you write a proportion that shows how much 5 gallons of gas will cost? Use x to represent the unknown cost.

Question

A. 15 : 45 :: x : 5
B. 15/45 = x/5
C. 15/45 = 5/x
D. 15/x = 45/5

Answer 1

To find a proportion that shows how much 5 gallons of gas will cost using fractional notation, we want to set up a ratio of gallons to cost.

The initial information tells us that 15 gallons of gas costs $45. We want to find the cost (x) for 5 gallons.

The correct proportion would be comparing the ratio of gallons to cost for both sets of information, which corresponds to choice C:

C. \( \frac{15}{45} = \frac{5}{x} \)

This proportion states that the ratio of 15 gallons to the cost of $45 is equal to the ratio of 5 gallons to the unknown cost \( x \).

So, the answer is C. 15/45 = 5/x.

Answer 2

are you sure this is correct

Answer 3

Let's reassess the problem step-by-step to ensure clarity in finding the correct proportion.

1. Understand the given information: You fill your car with 15 gallons of gas at a cost of $45.
2. Define what we need: We want to know the cost of 5 gallons of gas. We'll represent this unknown cost with \( x \).

We can set up a proportion relating the gallons to the cost:

\[ \text{The ratio of gallons to cost for the first scenario:} \quad \frac{15 \text{ gallons}}{45 \text{ dollars}} \]

We want to find the cost for 5 gallons, which we will represent as \( x \):

\[ \text{The ratio for the second scenario:} \quad \frac{5 \text{ gallons}}{x \text{ dollars}} \]

To set these two ratios equal (proportionate), we get:

\[ \frac{15}{45} = \frac{5}{x} \]

This matches option C: \( \frac{15}{45} = \frac{5}{x} \).

So after reviewing, C is indeed correct. The original analysis was accurate. Thank you for your patience!