Finding the Fourth Proportional to 105.05, 158.29 and 87.18

Step by Step Solution

1. Step 1: Write the proportion equation
   105.05 : 158.29 = 87.18 : x
2. Step 2: Convert to fraction form
   105.05/158.29 = 87.18/x
3. Step 3: Cross multiply
   105.05x = 158.29 × 87.18
4. Step 4: Simplify right side
   105.05x = 13,799.72
5. Step 5: Solve for x
   x = 13,799.72/105.05
6. Step 6: Final answer
   x = 131.36