Finding the Fourth Proportional to 123.39, 185.08 and 42.21

Step by Step Solution

1. Step 1: Write the proportion equation
   123.39 : 185.08 = 42.21 : x
2. Step 2: Convert to fraction form
   123.39/185.08 = 42.21/x
3. Step 3: Cross multiply
   123.39x = 185.08 × 42.21
4. Step 4: Simplify right side
   123.39x = 7,812.23
5. Step 5: Solve for x
   x = 7,812.23/123.39
6. Step 6: Final answer
   x = 63.31