Finding the Fourth Proportional to 311,978.70, 468,043.65 and 90,362.70

Step by Step Solution

1. Step 1: Write the proportion equation
   311,978.70 : 468,043.65 = 90,362.70 : x
2. Step 2: Convert to fraction form
   311,978.70/468,043.65 = 90,362.70/x
3. Step 3: Cross multiply
   311,978.70x = 468,043.65 × 90,362.70
4. Step 4: Simplify right side
   311,978.70x = 42,293,687,931.86
5. Step 5: Solve for x
   x = 42,293,687,931.86/311,978.70
6. Step 6: Final answer
   x = 135,565.95