Finding the Fourth Proportional to 99.69, 149.48 and 72.31

Step by Step Solution

1. Step 1: Write the proportion equation
   99.69 : 149.48 = 72.31 : x
2. Step 2: Convert to fraction form
   99.69/149.48 = 72.31/x
3. Step 3: Cross multiply
   99.69x = 149.48 × 72.31
4. Step 4: Simplify right side
   99.69x = 10,807.79
5. Step 5: Solve for x
   x = 10,807.79/99.69
6. Step 6: Final answer
   x = 108.42