Finding the Fourth Proportional to 1,003.35, 1,504.89 and 387.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,003.35 : 1,504.89 = 387.12 : x
2. Step 2: Convert to fraction form
   1,003.35/1,504.89 = 387.12/x
3. Step 3: Cross multiply
   1,003.35x = 1,504.89 × 387.12
4. Step 4: Simplify right side
   1,003.35x = 582,573.02
5. Step 5: Solve for x
   x = 582,573.02/1,003.35
6. Step 6: Final answer
   x = 580.63