Finding the Fourth Proportional to 1,139.59, 1,709.43 and 317.94

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.59 : 1,709.43 = 317.94 : x
2. Step 2: Convert to fraction form
   1,139.59/1,709.43 = 317.94/x
3. Step 3: Cross multiply
   1,139.59x = 1,709.43 × 317.94
4. Step 4: Simplify right side
   1,139.59x = 543,496.17
5. Step 5: Solve for x
   x = 543,496.17/1,139.59
6. Step 6: Final answer
   x = 476.92