Finding the Fourth Proportional to 100.89, 139.15 and 75.98

Step by Step Solution

1. Step 1: Write the proportion equation
   100.89 : 139.15 = 75.98 : x
2. Step 2: Convert to fraction form
   100.89/139.15 = 75.98/x
3. Step 3: Cross multiply
   100.89x = 139.15 × 75.98
4. Step 4: Simplify right side
   100.89x = 10,573.06
5. Step 5: Solve for x
   x = 10,573.06/100.89
6. Step 6: Final answer
   x = 104.80