Finding the Fourth Proportional to 105,132.43, 145,081.78 and 64,830.07

Step by Step Solution

1. Step 1: Write the proportion equation
   105,132.43 : 145,081.78 = 64,830.07 : x
2. Step 2: Convert to fraction form
   105,132.43/145,081.78 = 64,830.07/x
3. Step 3: Cross multiply
   105,132.43x = 145,081.78 × 64,830.07
4. Step 4: Simplify right side
   105,132.43x = 9,405,662,337.07
5. Step 5: Solve for x
   x = 9,405,662,337.07/105,132.43
6. Step 6: Final answer
   x = 89,464.90