A model of a boat is 1 3/8 feet long. How long is the model of a ship that is 3 times as long, I'd the models are made to the same scale?

3 * 11/8 = 33/8 = 4 1/8 feet

To find the length of the model ship, we need to multiply the length of the model boat by 3, since the ship is 3 times as long. Let's break down the calculation step-by-step:

1. Start with the length of the model boat: 1 3/8 feet.
2. Convert the mixed number to an improper fraction: 1 3/8 = (8 * 1 + 3) / 8 = 11/8 feet.
3. Multiply the length of the model boat by 3: 11/8 * 3 = 33/8 feet.
4. Simplify the fraction if necessary: Since 33 and 8 do not share any common factors other than 1, the fraction is already in its simplest form.
5. Convert the fraction back to a mixed number: 33/8 = 4 1/8 feet.

Therefore, the length of the model ship, made to the same scale as the model boat, is 4 1/8 feet.