Finding the Fourth Proportional to 99.90, 149.72 and 69.39

Step by Step Solution

1. Step 1: Write the proportion equation
   99.90 : 149.72 = 69.39 : x
2. Step 2: Convert to fraction form
   99.90/149.72 = 69.39/x
3. Step 3: Cross multiply
   99.90x = 149.72 × 69.39
4. Step 4: Simplify right side
   99.90x = 10,388.72
5. Step 5: Solve for x
   x = 10,388.72/99.90
6. Step 6: Final answer
   x = 103.99