Finding the Fourth Proportional to 102.96, 142.16 and 89.10

Step by Step Solution

1. Step 1: Write the proportion equation
   102.96 : 142.16 = 89.10 : x
2. Step 2: Convert to fraction form
   102.96/142.16 = 89.10/x
3. Step 3: Cross multiply
   102.96x = 142.16 × 89.10
4. Step 4: Simplify right side
   102.96x = 12,666.01
5. Step 5: Solve for x
   x = 12,666.01/102.96
6. Step 6: Final answer
   x = 123.02