Finding the Fourth Proportional to 90.89, 136.23 and 42.17

Step by Step Solution

1. Step 1: Write the proportion equation
   90.89 : 136.23 = 42.17 : x
2. Step 2: Convert to fraction form
   90.89/136.23 = 42.17/x
3. Step 3: Cross multiply
   90.89x = 136.23 × 42.17
4. Step 4: Simplify right side
   90.89x = 5,744.82
5. Step 5: Solve for x
   x = 5,744.82/90.89
6. Step 6: Final answer
   x = 63.21