Finding the Fourth Proportional to 66,571.72, 91,875.78 and 64,506.76

Step by Step Solution

1. Step 1: Write the proportion equation
   66,571.72 : 91,875.78 = 64,506.76 : x
2. Step 2: Convert to fraction form
   66,571.72/91,875.78 = 64,506.76/x
3. Step 3: Cross multiply
   66,571.72x = 91,875.78 × 64,506.76
4. Step 4: Simplify right side
   66,571.72x = 5,926,608,890.27
5. Step 5: Solve for x
   x = 5,926,608,890.27/66,571.72
6. Step 6: Final answer
   x = 89,025.92