Finding the Fourth Proportional to 1,003.86, 1,385.34 and 561.74

Step by Step Solution

1. Step 1: Write the proportion equation
   1,003.86 : 1,385.34 = 561.74 : x
2. Step 2: Convert to fraction form
   1,003.86/1,385.34 = 561.74/x
3. Step 3: Cross multiply
   1,003.86x = 1,385.34 × 561.74
4. Step 4: Simplify right side
   1,003.86x = 778,191.86
5. Step 5: Solve for x
   x = 778,191.86/1,003.86
6. Step 6: Final answer
   x = 775.20