Finding the Fourth Proportional to 90,870.39, 136,318.55 and 28,545.75

Step by Step Solution

1. Step 1: Write the proportion equation
   90,870.39 : 136,318.55 = 28,545.75 : x
2. Step 2: Convert to fraction form
   90,870.39/136,318.55 = 28,545.75/x
3. Step 3: Cross multiply
   90,870.39x = 136,318.55 × 28,545.75
4. Step 4: Simplify right side
   90,870.39x = 3,891,315,105.93
5. Step 5: Solve for x
   x = 3,891,315,105.93/90,870.39
6. Step 6: Final answer
   x = 42,822.70