Finding the Fourth Proportional to 100.72, 151.12 and 86.80

Step by Step Solution

1. Step 1: Write the proportion equation
   100.72 : 151.12 = 86.80 : x
2. Step 2: Convert to fraction form
   100.72/151.12 = 86.80/x
3. Step 3: Cross multiply
   100.72x = 151.12 × 86.80
4. Step 4: Simplify right side
   100.72x = 13,117.22
5. Step 5: Solve for x
   x = 13,117.22/100.72
6. Step 6: Final answer
   x = 130.23