Finding the Fourth Proportional to 123.86, 185.92 and 78.10

Step by Step Solution

1. Step 1: Write the proportion equation
   123.86 : 185.92 = 78.10 : x
2. Step 2: Convert to fraction form
   123.86/185.92 = 78.10/x
3. Step 3: Cross multiply
   123.86x = 185.92 × 78.10
4. Step 4: Simplify right side
   123.86x = 14,520.35
5. Step 5: Solve for x
   x = 14,520.35/123.86
6. Step 6: Final answer
   x = 117.23