Finding the Fourth Proportional to 91,933.31, 138,016.62 and 78,169.79

Step by Step Solution

1. Step 1: Write the proportion equation
   91,933.31 : 138,016.62 = 78,169.79 : x
2. Step 2: Convert to fraction form
   91,933.31/138,016.62 = 78,169.79/x
3. Step 3: Cross multiply
   91,933.31x = 138,016.62 × 78,169.79
4. Step 4: Simplify right side
   91,933.31x = 10,788,729,511.83
5. Step 5: Solve for x
   x = 10,788,729,511.83/91,933.31
6. Step 6: Final answer
   x = 117,353.87