Finding the Fourth Proportional to 123.78, 185.72 and 78.08

Step by Step Solution

1. Step 1: Write the proportion equation
   123.78 : 185.72 = 78.08 : x
2. Step 2: Convert to fraction form
   123.78/185.72 = 78.08/x
3. Step 3: Cross multiply
   123.78x = 185.72 × 78.08
4. Step 4: Simplify right side
   123.78x = 14,499.70
5. Step 5: Solve for x
   x = 14,499.70/123.78
6. Step 6: Final answer
   x = 117.14