Finding the Fourth Proportional to 90.76, 136.09 and 42.63

Step by Step Solution

1. Step 1: Write the proportion equation
   90.76 : 136.09 = 42.63 : x
2. Step 2: Convert to fraction form
   90.76/136.09 = 42.63/x
3. Step 3: Cross multiply
   90.76x = 136.09 × 42.63
4. Step 4: Simplify right side
   90.76x = 5,801.52
5. Step 5: Solve for x
   x = 5,801.52/90.76
6. Step 6: Final answer
   x = 63.92