Finding the Fourth Proportional to 90.95, 136.38 and 42.20

Step by Step Solution

1. Step 1: Write the proportion equation
   90.95 : 136.38 = 42.20 : x
2. Step 2: Convert to fraction form
   90.95/136.38 = 42.20/x
3. Step 3: Cross multiply
   90.95x = 136.38 × 42.20
4. Step 4: Simplify right side
   90.95x = 5,754.55
5. Step 5: Solve for x
   x = 5,754.55/90.95
6. Step 6: Final answer
   x = 63.28