Finding the Fourth Proportional to 1,490.72, 2,057.56 and 861.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,490.72 : 2,057.56 = 861.61 : x
2. Step 2: Convert to fraction form
   1,490.72/2,057.56 = 861.61/x
3. Step 3: Cross multiply
   1,490.72x = 2,057.56 × 861.61
4. Step 4: Simplify right side
   1,490.72x = 1,772,814.27
5. Step 5: Solve for x
   x = 1,772,814.27/1,490.72
6. Step 6: Final answer
   x = 1,189.23