Finding the Fourth Proportional to 102.43, 141.07 and 89.31

Step by Step Solution

1. Step 1: Write the proportion equation
   102.43 : 141.07 = 89.31 : x
2. Step 2: Convert to fraction form
   102.43/141.07 = 89.31/x
3. Step 3: Cross multiply
   102.43x = 141.07 × 89.31
4. Step 4: Simplify right side
   102.43x = 12,598.96
5. Step 5: Solve for x
   x = 12,598.96/102.43
6. Step 6: Final answer
   x = 123.00