Finding the Fourth Proportional to 1,581.90, 2,182.95 and 918.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,581.90 : 2,182.95 = 918.71 : x
2. Step 2: Convert to fraction form
   1,581.90/2,182.95 = 918.71/x
3. Step 3: Cross multiply
   1,581.90x = 2,182.95 × 918.71
4. Step 4: Simplify right side
   1,581.90x = 2,005,495.27
5. Step 5: Solve for x
   x = 2,005,495.27/1,581.90
6. Step 6: Final answer
   x = 1,267.78