Finding the Fourth Proportional to 115,291.50, 159,104.70 and 64,990.50

Step by Step Solution

1. Step 1: Write the proportion equation
   115,291.50 : 159,104.70 = 64,990.50 : x
2. Step 2: Convert to fraction form
   115,291.50/159,104.70 = 64,990.50/x
3. Step 3: Cross multiply
   115,291.50x = 159,104.70 × 64,990.50
4. Step 4: Simplify right side
   115,291.50x = 10,340,294,005.35
5. Step 5: Solve for x
   x = 10,340,294,005.35/115,291.50
6. Step 6: Final answer
   x = 89,688.26