Finding the Fourth Proportional to 1,123,215.39, 1,549,858.05 and 639,790.11

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123,215.39 : 1,549,858.05 = 639,790.11 : x
2. Step 2: Convert to fraction form
   1,123,215.39/1,549,858.05 = 639,790.11/x
3. Step 3: Cross multiply
   1,123,215.39x = 1,549,858.05 × 639,790.11
4. Step 4: Simplify right side
   1,123,215.39x = 991,583,852,293.89
5. Step 5: Solve for x
   x = 991,583,852,293.89/1,123,215.39
6. Step 6: Final answer
   x = 882,808.29