Question

25. Penelope was asked to determine the ratio

of cars to trucks crossing the Pennybacker
Bridge for a week. She reported that the
ratio of cars to trucks was 11 to 7. Her
supervisor looked over her work and
saw she forgot to include two cars in her
tally. She changed her ratio to 13 to 7. Her
supervisor says you cannot just add these
to the ratio since over 100 cars crossed
the bridge this week. Explain why her
supervisor is correct.

Answer 1

Penelope's supervisor is correct because you can't just add the two additional cars to the ratio. To find the new ratio, you can set up a proportion using the given ratio and the total number of cars.

Step-by-step explanation:

Penelope's supervisor is correct because you can't just add the two additional cars to the ratio. To determine the new ratio, you need to consider the total number of cars that crossed the bridge.

If there were over 100 cars, then adding just two cars to the numerator of the ratio would not accurately represent the proportion of cars to trucks.

To find the new ratio, you can set up a proportion using the given ratio and the total number of cars:

(11/7) = (x/100)

Cross multiplying and solving, you get:

7x = 1100

x = 157.14

Since you can't have a fraction of a car, you would round x to the nearest whole number, which is 157.