Finding the Fourth Proportional to 42,906.38, 64,379.00 and 20,715.62

Step by Step Solution

1. Step 1: Write the proportion equation
   42,906.38 : 64,379.00 = 20,715.62 : x
2. Step 2: Convert to fraction form
   42,906.38/64,379.00 = 20,715.62/x
3. Step 3: Cross multiply
   42,906.38x = 64,379.00 × 20,715.62
4. Step 4: Simplify right side
   42,906.38x = 1,333,650,629.87
5. Step 5: Solve for x
   x = 1,333,650,629.87/42,906.38
6. Step 6: Final answer
   x = 31,082.81