Finding the Fourth Proportional to 86.29, 129.43 and 42.98

Step by Step Solution

1. Step 1: Write the proportion equation
   86.29 : 129.43 = 42.98 : x
2. Step 2: Convert to fraction form
   86.29/129.43 = 42.98/x
3. Step 3: Cross multiply
   86.29x = 129.43 × 42.98
4. Step 4: Simplify right side
   86.29x = 5,562.31
5. Step 5: Solve for x
   x = 5,562.31/86.29
6. Step 6: Final answer
   x = 64.46