Finding the Fourth Proportional to 1,123,139.38, 1,550,207.74 and 639,989.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123,139.38 : 1,550,207.74 = 639,989.32 : x
2. Step 2: Convert to fraction form
   1,123,139.38/1,550,207.74 = 639,989.32/x
3. Step 3: Cross multiply
   1,123,139.38x = 1,550,207.74 × 639,989.32
4. Step 4: Simplify right side
   1,123,139.38x = 992,116,397,381.34
5. Step 5: Solve for x
   x = 992,116,397,381.34/1,123,139.38
6. Step 6: Final answer
   x = 883,342.19