Finding the Fourth Proportional to 1,490.98, 2,057.76 and 861.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,490.98 : 2,057.76 = 861.38 : x
2. Step 2: Convert to fraction form
   1,490.98/2,057.76 = 861.38/x
3. Step 3: Cross multiply
   1,490.98x = 2,057.76 × 861.38
4. Step 4: Simplify right side
   1,490.98x = 1,772,513.31
5. Step 5: Solve for x
   x = 1,772,513.31/1,490.98
6. Step 6: Final answer
   x = 1,188.82