Finding the Fourth Proportional to 158.61, 238.18 and 86.52

Step by Step Solution

1. Step 1: Write the proportion equation
   158.61 : 238.18 = 86.52 : x
2. Step 2: Convert to fraction form
   158.61/238.18 = 86.52/x
3. Step 3: Cross multiply
   158.61x = 238.18 × 86.52
4. Step 4: Simplify right side
   158.61x = 20,607.33
5. Step 5: Solve for x
   x = 20,607.33/158.61
6. Step 6: Final answer
   x = 129.92