Finding the Fourth Proportional to 123.57, 185.31 and 42.39

Step by Step Solution

1. Step 1: Write the proportion equation
   123.57 : 185.31 = 42.39 : x
2. Step 2: Convert to fraction form
   123.57/185.31 = 42.39/x
3. Step 3: Cross multiply
   123.57x = 185.31 × 42.39
4. Step 4: Simplify right side
   123.57x = 7,855.29
5. Step 5: Solve for x
   x = 7,855.29/123.57
6. Step 6: Final answer
   x = 63.57