Finding the Fourth Proportional to 100.53, 150.55 and 86.00

Step by Step Solution

1. Step 1: Write the proportion equation
   100.53 : 150.55 = 86.00 : x
2. Step 2: Convert to fraction form
   100.53/150.55 = 86.00/x
3. Step 3: Cross multiply
   100.53x = 150.55 × 86.00
4. Step 4: Simplify right side
   100.53x = 12,947.46
5. Step 5: Solve for x
   x = 12,947.46/100.53
6. Step 6: Final answer
   x = 128.79