Finding the Fourth Proportional to 42,128.94, 58,138.34 and 23,978.78

Step by Step Solution

1. Step 1: Write the proportion equation
   42,128.94 : 58,138.34 = 23,978.78 : x
2. Step 2: Convert to fraction form
   42,128.94/58,138.34 = 23,978.78/x
3. Step 3: Cross multiply
   42,128.94x = 58,138.34 × 23,978.78
4. Step 4: Simplify right side
   42,128.94x = 1,394,086,404.48
5. Step 5: Solve for x
   x = 1,394,086,404.48/42,128.94
6. Step 6: Final answer
   x = 33,090.94