Finding the Fourth Proportional to 89,903.21, 123,996.32 and 57,640.91

Step by Step Solution

1. Step 1: Write the proportion equation
   89,903.21 : 123,996.32 = 57,640.91 : x
2. Step 2: Convert to fraction form
   89,903.21/123,996.32 = 57,640.91/x
3. Step 3: Cross multiply
   89,903.21x = 123,996.32 × 57,640.91
4. Step 4: Simplify right side
   89,903.21x = 7,147,259,813.27
5. Step 5: Solve for x
   x = 7,147,259,813.27/89,903.21
6. Step 6: Final answer
   x = 79,499.50