Finding the Fourth Proportional to 90.75, 136.16 and 42.63

Step by Step Solution

1. Step 1: Write the proportion equation
   90.75 : 136.16 = 42.63 : x
2. Step 2: Convert to fraction form
   90.75/136.16 = 42.63/x
3. Step 3: Cross multiply
   90.75x = 136.16 × 42.63
4. Step 4: Simplify right side
   90.75x = 5,804.50
5. Step 5: Solve for x
   x = 5,804.50/90.75
6. Step 6: Final answer
   x = 63.96