Finding the Fourth Proportional to 100,212.72, 137,978.82 and 85,074

Step by Step Solution

1. Step 1: Write the proportion equation
   100,212.72 : 137,978.82 = 85,074 : x
2. Step 2: Convert to fraction form
   100,212.72/137,978.82 = 85,074/x
3. Step 3: Cross multiply
   100,212.72x = 137,978.82 × 85,074
4. Step 4: Simplify right side
   100,212.72x = 11,738,410,132.68
5. Step 5: Solve for x
   x = 11,738,410,132.68/100,212.72
6. Step 6: Final answer
   x = 117,134.93