Finding the Fourth Proportional to 1,005.60, 1,387.52 and 591.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.60 : 1,387.52 = 591.60 : x
2. Step 2: Convert to fraction form
   1,005.60/1,387.52 = 591.60/x
3. Step 3: Cross multiply
   1,005.60x = 1,387.52 × 591.60
4. Step 4: Simplify right side
   1,005.60x = 820,856.83
5. Step 5: Solve for x
   x = 820,856.83/1,005.60
6. Step 6: Final answer
   x = 816.29