Finding the Fourth Proportional to 287,667.62, 431,518.71 and 87,989.73

Step by Step Solution

1. Step 1: Write the proportion equation
   287,667.62 : 431,518.71 = 87,989.73 : x
2. Step 2: Convert to fraction form
   287,667.62/431,518.71 = 87,989.73/x
3. Step 3: Cross multiply
   287,667.62x = 431,518.71 × 87,989.73
4. Step 4: Simplify right side
   287,667.62x = 37,969,214,782.85
5. Step 5: Solve for x
   x = 37,969,214,782.85/287,667.62
6. Step 6: Final answer
   x = 131,989.88