Finding the Fourth Proportional to 86.91, 130.31 and 43.49

Step by Step Solution

1. Step 1: Write the proportion equation
   86.91 : 130.31 = 43.49 : x
2. Step 2: Convert to fraction form
   86.91/130.31 = 43.49/x
3. Step 3: Cross multiply
   86.91x = 130.31 × 43.49
4. Step 4: Simplify right side
   86.91x = 5,667.62
5. Step 5: Solve for x
   x = 5,667.62/86.91
6. Step 6: Final answer
   x = 65.21