Finding the Fourth Proportional to 102.72, 141.74 and 89.01

Step by Step Solution

1. Step 1: Write the proportion equation
   102.72 : 141.74 = 89.01 : x
2. Step 2: Convert to fraction form
   102.72/141.74 = 89.01/x
3. Step 3: Cross multiply
   102.72x = 141.74 × 89.01
4. Step 4: Simplify right side
   102.72x = 12,615.83
5. Step 5: Solve for x
   x = 12,615.83/102.72
6. Step 6: Final answer
   x = 122.82