Finding the Fourth Proportional to 31,129.52, 42,975.77 and 21,945.33

Step by Step Solution

1. Step 1: Write the proportion equation
   31,129.52 : 42,975.77 = 21,945.33 : x
2. Step 2: Convert to fraction form
   31,129.52/42,975.77 = 21,945.33/x
3. Step 3: Cross multiply
   31,129.52x = 42,975.77 × 21,945.33
4. Step 4: Simplify right side
   31,129.52x = 943,117,344.93
5. Step 5: Solve for x
   x = 943,117,344.93/31,129.52
6. Step 6: Final answer
   x = 30,296.56