Finding the Fourth Proportional to 1,003.39, 1,504.31 and 613.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,003.39 : 1,504.31 = 613.57 : x
2. Step 2: Convert to fraction form
   1,003.39/1,504.31 = 613.57/x
3. Step 3: Cross multiply
   1,003.39x = 1,504.31 × 613.57
4. Step 4: Simplify right side
   1,003.39x = 922,998.93
5. Step 5: Solve for x
   x = 922,998.93/1,003.39
6. Step 6: Final answer
   x = 919.88