Finding the Fourth Proportional to 1,581.72, 2,182.70 and 918.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,581.72 : 2,182.70 = 918.60 : x
2. Step 2: Convert to fraction form
   1,581.72/2,182.70 = 918.60/x
3. Step 3: Cross multiply
   1,581.72x = 2,182.70 × 918.60
4. Step 4: Simplify right side
   1,581.72x = 2,005,028.22
5. Step 5: Solve for x
   x = 2,005,028.22/1,581.72
6. Step 6: Final answer
   x = 1,267.63