Finding the Fourth Proportional to 100.91, 151.16 and 86.33

Step by Step Solution

1. Step 1: Write the proportion equation
   100.91 : 151.16 = 86.33 : x
2. Step 2: Convert to fraction form
   100.91/151.16 = 86.33/x
3. Step 3: Cross multiply
   100.91x = 151.16 × 86.33
4. Step 4: Simplify right side
   100.91x = 13,048.46
5. Step 5: Solve for x
   x = 13,048.46/100.91
6. Step 6: Final answer
   x = 129.31