Finding the Fourth Proportional to 1,580.29, 2,179.89 and 917.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,580.29 : 2,179.89 = 917.06 : x
2. Step 2: Convert to fraction form
   1,580.29/2,179.89 = 917.06/x
3. Step 3: Cross multiply
   1,580.29x = 2,179.89 × 917.06
4. Step 4: Simplify right side
   1,580.29x = 1,999,079.02
5. Step 5: Solve for x
   x = 1,999,079.02/1,580.29
6. Step 6: Final answer
   x = 1,265.01