Finding the Fourth Proportional to 100.98, 139.23 and 89.37

Step by Step Solution

1. Step 1: Write the proportion equation
   100.98 : 139.23 = 89.37 : x
2. Step 2: Convert to fraction form
   100.98/139.23 = 89.37/x
3. Step 3: Cross multiply
   100.98x = 139.23 × 89.37
4. Step 4: Simplify right side
   100.98x = 12,442.99
5. Step 5: Solve for x
   x = 12,442.99/100.98
6. Step 6: Final answer
   x = 123.22