Finding the Fourth Proportional to 100.12, 150.17 and 42.31

Step by Step Solution

1. Step 1: Write the proportion equation
   100.12 : 150.17 = 42.31 : x
2. Step 2: Convert to fraction form
   100.12/150.17 = 42.31/x
3. Step 3: Cross multiply
   100.12x = 150.17 × 42.31
4. Step 4: Simplify right side
   100.12x = 6,353.69
5. Step 5: Solve for x
   x = 6,353.69/100.12
6. Step 6: Final answer
   x = 63.46