Finding the Fourth Proportional to 1,580.30, 2,180.46 and 916.77

Step by Step Solution

1. Step 1: Write the proportion equation
   1,580.30 : 2,180.46 = 916.77 : x
2. Step 2: Convert to fraction form
   1,580.30/2,180.46 = 916.77/x
3. Step 3: Cross multiply
   1,580.30x = 2,180.46 × 916.77
4. Step 4: Simplify right side
   1,580.30x = 1,998,978.74
5. Step 5: Solve for x
   x = 1,998,978.74/1,580.30
6. Step 6: Final answer
   x = 1,264.94