Finding the Fourth Proportional to 56,613.39, 78,128.31 and 31,120.59

Step by Step Solution

1. Step 1: Write the proportion equation
   56,613.39 : 78,128.31 = 31,120.59 : x
2. Step 2: Convert to fraction form
   56,613.39/78,128.31 = 31,120.59/x
3. Step 3: Cross multiply
   56,613.39x = 78,128.31 × 31,120.59
4. Step 4: Simplify right side
   56,613.39x = 2,431,399,102.90
5. Step 5: Solve for x
   x = 2,431,399,102.90/56,613.39
6. Step 6: Final answer
   x = 42,947.42