Finding the Fourth Proportional to 1,039.59, 1,434.15 and 619.70

Step by Step Solution

1. Step 1: Write the proportion equation
   1,039.59 : 1,434.15 = 619.70 : x
2. Step 2: Convert to fraction form
   1,039.59/1,434.15 = 619.70/x
3. Step 3: Cross multiply
   1,039.59x = 1,434.15 × 619.70
4. Step 4: Simplify right side
   1,039.59x = 888,735.58
5. Step 5: Solve for x
   x = 888,735.58/1,039.59
6. Step 6: Final answer
   x = 854.89