Finding the Fourth Proportional to 1,377.50, 2,066.31 and 403.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,377.50 : 2,066.31 = 403.61 : x
2. Step 2: Convert to fraction form
   1,377.50/2,066.31 = 403.61/x
3. Step 3: Cross multiply
   1,377.50x = 2,066.31 × 403.61
4. Step 4: Simplify right side
   1,377.50x = 833,973.05
5. Step 5: Solve for x
   x = 833,973.05/1,377.50
6. Step 6: Final answer
   x = 605.43