Finding the Fourth Proportional to 123.85, 185.59 and 78.09

Step by Step Solution

1. Step 1: Write the proportion equation
   123.85 : 185.59 = 78.09 : x
2. Step 2: Convert to fraction form
   123.85/185.59 = 78.09/x
3. Step 3: Cross multiply
   123.85x = 185.59 × 78.09
4. Step 4: Simplify right side
   123.85x = 14,492.72
5. Step 5: Solve for x
   x = 14,492.72/123.85
6. Step 6: Final answer
   x = 117.02