To determine the amount of meat needed for 100 guests, we start by establishing the proportion based on the information given.
From the caterer's data:
- For 25 guests, 40 pounds of meat is needed.
We can set up the proportion as follows:
\[ \frac{40 \text{ pounds}}{25 \text{ guests}} = \frac{x \text{ pounds}}{100 \text{ guests}} \]
Now, we can solve for \(x\):
- Cross-multiply to find \(x\):
\[ 40 \text{ pounds} \times 100 \text{ guests} = 25 \text{ guests} \times x \text{ pounds} \]
\[ 4000 = 25x \]
- Now, divide both sides by 25:
\[ x = \frac{4000}{25} = 160 \]
The caterer should order 160 pounds of meat for 100 guests.
Thus, the answer is 160 pounds.