Finding the Fourth Proportional to 99.55, 137.42 and 89.17

Step by Step Solution

1. Step 1: Write the proportion equation
   99.55 : 137.42 = 89.17 : x
2. Step 2: Convert to fraction form
   99.55/137.42 = 89.17/x
3. Step 3: Cross multiply
   99.55x = 137.42 × 89.17
4. Step 4: Simplify right side
   99.55x = 12,253.52
5. Step 5: Solve for x
   x = 12,253.52/99.55
6. Step 6: Final answer
   x = 123.09