Finding the Fourth Proportional to 123.81, 185.72 and 42.65

Step by Step Solution

1. Step 1: Write the proportion equation
   123.81 : 185.72 = 42.65 : x
2. Step 2: Convert to fraction form
   123.81/185.72 = 42.65/x
3. Step 3: Cross multiply
   123.81x = 185.72 × 42.65
4. Step 4: Simplify right side
   123.81x = 7,919.82
5. Step 5: Solve for x
   x = 7,919.82/123.81
6. Step 6: Final answer
   x = 63.97