Finding the Fourth Proportional to 100.99, 139.42 and 69.89

Step by Step Solution

1. Step 1: Write the proportion equation
   100.99 : 139.42 = 69.89 : x
2. Step 2: Convert to fraction form
   100.99/139.42 = 69.89/x
3. Step 3: Cross multiply
   100.99x = 139.42 × 69.89
4. Step 4: Simplify right side
   100.99x = 9,744.06
5. Step 5: Solve for x
   x = 9,744.06/100.99
6. Step 6: Final answer
   x = 96.49