Finding the Fourth Proportional to 287,667.67, 431,518.81 and 87,989.79

Step by Step Solution

1. Step 1: Write the proportion equation
   287,667.67 : 431,518.81 = 87,989.79 : x
2. Step 2: Convert to fraction form
   287,667.67/431,518.81 = 87,989.79/x
3. Step 3: Cross multiply
   287,667.67x = 431,518.81 × 87,989.79
4. Step 4: Simplify right side
   287,667.67x = 37,969,249,472.95
5. Step 5: Solve for x
   x = 37,969,249,472.95/287,667.67
6. Step 6: Final answer
   x = 131,989.98