Finding the Fourth Proportional to 123.79, 185.72 and 72.42

Step by Step Solution

1. Step 1: Write the proportion equation
   123.79 : 185.72 = 72.42 : x
2. Step 2: Convert to fraction form
   123.79/185.72 = 72.42/x
3. Step 3: Cross multiply
   123.79x = 185.72 × 72.42
4. Step 4: Simplify right side
   123.79x = 13,449.48
5. Step 5: Solve for x
   x = 13,449.48/123.79
6. Step 6: Final answer
   x = 108.65