Finding the Fourth Proportional to 100.56, 150.78 and 87.10

Step by Step Solution

1. Step 1: Write the proportion equation
   100.56 : 150.78 = 87.10 : x
2. Step 2: Convert to fraction form
   100.56/150.78 = 87.10/x
3. Step 3: Cross multiply
   100.56x = 150.78 × 87.10
4. Step 4: Simplify right side
   100.56x = 13,132.56
5. Step 5: Solve for x
   x = 13,132.56/100.56
6. Step 6: Final answer
   x = 130.59