Finding the Fourth Proportional to 151.69, 209.42 and 99.31

Step by Step Solution

1. Step 1: Write the proportion equation
   151.69 : 209.42 = 99.31 : x
2. Step 2: Convert to fraction form
   151.69/209.42 = 99.31/x
3. Step 3: Cross multiply
   151.69x = 209.42 × 99.31
4. Step 4: Simplify right side
   151.69x = 20,797.50
5. Step 5: Solve for x
   x = 20,797.50/151.69
6. Step 6: Final answer
   x = 137.11