Finding the Fourth Proportional to 123.71, 185.15 and 71.57

Step by Step Solution

1. Step 1: Write the proportion equation
   123.71 : 185.15 = 71.57 : x
2. Step 2: Convert to fraction form
   123.71/185.15 = 71.57/x
3. Step 3: Cross multiply
   123.71x = 185.15 × 71.57
4. Step 4: Simplify right side
   123.71x = 13,251.83
5. Step 5: Solve for x
   x = 13,251.83/123.71
6. Step 6: Final answer
   x = 107.12