Finding the Third Proportional to 274.80 and 417.89

Step by Step Solution

1. Step 1: Write the proportion equation
   274.80 : 417.89 = 417.89 : x
2. Step 2: Convert to fraction form
   274.80/417.89 = 417.89/x
3. Step 3: Cross multiply
   274.80x = 417.89 × 417.89
4. Step 4: Simplify right side
   274.80x = 174,635.02
5. Step 5: Solve for x
   x = 174,635.02/274.80
6. Step 6: Final answer
   x = 635.50