Finding the Fourth Proportional to 123.98, 185.98 and 42.79

Step by Step Solution

1. Step 1: Write the proportion equation
   123.98 : 185.98 = 42.79 : x
2. Step 2: Convert to fraction form
   123.98/185.98 = 42.79/x
3. Step 3: Cross multiply
   123.98x = 185.98 × 42.79
4. Step 4: Simplify right side
   123.98x = 7,958.08
5. Step 5: Solve for x
   x = 7,958.08/123.98
6. Step 6: Final answer
   x = 64.19