Finding the Fourth Proportional to 1,139.94, 1,710.18 and 817.74

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.94 : 1,710.18 = 817.74 : x
2. Step 2: Convert to fraction form
   1,139.94/1,710.18 = 817.74/x
3. Step 3: Cross multiply
   1,139.94x = 1,710.18 × 817.74
4. Step 4: Simplify right side
   1,139.94x = 1,398,482.59
5. Step 5: Solve for x
   x = 1,398,482.59/1,139.94
6. Step 6: Final answer
   x = 1,226.80