Finding the Fourth Proportional to 1,005.32, 1,387.50 and 580.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.32 : 1,387.50 = 580.12 : x
2. Step 2: Convert to fraction form
   1,005.32/1,387.50 = 580.12/x
3. Step 3: Cross multiply
   1,005.32x = 1,387.50 × 580.12
4. Step 4: Simplify right side
   1,005.32x = 804,916.50
5. Step 5: Solve for x
   x = 804,916.50/1,005.32
6. Step 6: Final answer
   x = 800.66