Finding the Fourth Proportional to 121,105.56, 167,031 and 78,677.76

Step by Step Solution

1. Step 1: Write the proportion equation
   121,105.56 : 167,031 = 78,677.76 : x
2. Step 2: Convert to fraction form
   121,105.56/167,031 = 78,677.76/x
3. Step 3: Cross multiply
   121,105.56x = 167,031 × 78,677.76
4. Step 4: Simplify right side
   121,105.56x = 13,141,624,930.56
5. Step 5: Solve for x
   x = 13,141,624,930.56/121,105.56
6. Step 6: Final answer
   x = 108,513.80