Finding the Fourth Proportional to 1,580.83, 2,181.98 and 917.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,580.83 : 2,181.98 = 917.55 : x
2. Step 2: Convert to fraction form
   1,580.83/2,181.98 = 917.55/x
3. Step 3: Cross multiply
   1,580.83x = 2,181.98 × 917.55
4. Step 4: Simplify right side
   1,580.83x = 2,002,071.16
5. Step 5: Solve for x
   x = 2,002,071.16/1,580.83
6. Step 6: Final answer
   x = 1,266.47