Finding the Fourth Proportional to 85,870.43, 128,781.04 and 28,938.12

Step by Step Solution

1. Step 1: Write the proportion equation
   85,870.43 : 128,781.04 = 28,938.12 : x
2. Step 2: Convert to fraction form
   85,870.43/128,781.04 = 28,938.12/x
3. Step 3: Cross multiply
   85,870.43x = 128,781.04 × 28,938.12
4. Step 4: Simplify right side
   85,870.43x = 3,726,681,189.24
5. Step 5: Solve for x
   x = 3,726,681,189.24/85,870.43
6. Step 6: Final answer
   x = 43,398.89