Finding the Fourth Proportional to 123,640.79, 185,172.77 and 90,278.10

Step by Step Solution

1. Step 1: Write the proportion equation
   123,640.79 : 185,172.77 = 90,278.10 : x
2. Step 2: Convert to fraction form
   123,640.79/185,172.77 = 90,278.10/x
3. Step 3: Cross multiply
   123,640.79x = 185,172.77 × 90,278.10
4. Step 4: Simplify right side
   123,640.79x = 16,717,045,565.22
5. Step 5: Solve for x
   x = 16,717,045,565.22/123,640.79
6. Step 6: Final answer
   x = 135,206.56