Finding the Fourth Proportional to 1,003.91, 1,385.39 and 561.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,003.91 : 1,385.39 = 561.83 : x
2. Step 2: Convert to fraction form
   1,003.91/1,385.39 = 561.83/x
3. Step 3: Cross multiply
   1,003.91x = 1,385.39 × 561.83
4. Step 4: Simplify right side
   1,003.91x = 778,343.93
5. Step 5: Solve for x
   x = 778,343.93/1,003.91
6. Step 6: Final answer
   x = 775.32