Finding the Fourth Proportional to 1,490.38, 2,057.72 and 931.64

Step by Step Solution

1. Step 1: Write the proportion equation
   1,490.38 : 2,057.72 = 931.64 : x
2. Step 2: Convert to fraction form
   1,490.38/2,057.72 = 931.64/x
3. Step 3: Cross multiply
   1,490.38x = 2,057.72 × 931.64
4. Step 4: Simplify right side
   1,490.38x = 1,917,039.31
5. Step 5: Solve for x
   x = 1,917,039.31/1,490.38
6. Step 6: Final answer
   x = 1,286.28