Finding the Fourth Proportional to 91,990.89, 138,039.49 and 38,678.61

Step by Step Solution

1. Step 1: Write the proportion equation
   91,990.89 : 138,039.49 = 38,678.61 : x
2. Step 2: Convert to fraction form
   91,990.89/138,039.49 = 38,678.61/x
3. Step 3: Cross multiply
   91,990.89x = 138,039.49 × 38,678.61
4. Step 4: Simplify right side
   91,990.89x = 5,339,176,164.31
5. Step 5: Solve for x
   x = 5,339,176,164.31/91,990.89
6. Step 6: Final answer
   x = 58,040.27