Finding the Fourth Proportional to 31,321.33, 46,977.43 and 9,128.75

Step by Step Solution

1. Step 1: Write the proportion equation
   31,321.33 : 46,977.43 = 9,128.75 : x
2. Step 2: Convert to fraction form
   31,321.33/46,977.43 = 9,128.75/x
3. Step 3: Cross multiply
   31,321.33x = 46,977.43 × 9,128.75
4. Step 4: Simplify right side
   31,321.33x = 428,844,956.40
5. Step 5: Solve for x
   x = 428,844,956.40/31,321.33
6. Step 6: Final answer
   x = 13,691.79