Finding the Fourth Proportional to 100.39, 150.61 and 42.61

Step by Step Solution

1. Step 1: Write the proportion equation
   100.39 : 150.61 = 42.61 : x
2. Step 2: Convert to fraction form
   100.39/150.61 = 42.61/x
3. Step 3: Cross multiply
   100.39x = 150.61 × 42.61
4. Step 4: Simplify right side
   100.39x = 6,417.68
5. Step 5: Solve for x
   x = 6,417.68/100.39
6. Step 6: Final answer
   x = 63.93