Finding the Fourth Proportional to 1,139.84, 1,710.72 and 456.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.84 : 1,710.72 = 456.32 : x
2. Step 2: Convert to fraction form
   1,139.84/1,710.72 = 456.32/x
3. Step 3: Cross multiply
   1,139.84x = 1,710.72 × 456.32
4. Step 4: Simplify right side
   1,139.84x = 780,635.75
5. Step 5: Solve for x
   x = 780,635.75/1,139.84
6. Step 6: Final answer
   x = 684.86