Finding the Fourth Proportional to 100.35, 138.55 and 89.83

Step by Step Solution

1. Step 1: Write the proportion equation
   100.35 : 138.55 = 89.83 : x
2. Step 2: Convert to fraction form
   100.35/138.55 = 89.83/x
3. Step 3: Cross multiply
   100.35x = 138.55 × 89.83
4. Step 4: Simplify right side
   100.35x = 12,446.02
5. Step 5: Solve for x
   x = 12,446.02/100.35
6. Step 6: Final answer
   x = 124.02