Finding the Fourth Proportional to 123.39, 185.49 and 105.57

Step by Step Solution

1. Step 1: Write the proportion equation
   123.39 : 185.49 = 105.57 : x
2. Step 2: Convert to fraction form
   123.39/185.49 = 105.57/x
3. Step 3: Cross multiply
   123.39x = 185.49 × 105.57
4. Step 4: Simplify right side
   123.39x = 19,582.18
5. Step 5: Solve for x
   x = 19,582.18/123.39
6. Step 6: Final answer
   x = 158.70