Finding the Fourth Proportional to 90.89, 136.28 and 42.75

Step by Step Solution

1. Step 1: Write the proportion equation
   90.89 : 136.28 = 42.75 : x
2. Step 2: Convert to fraction form
   90.89/136.28 = 42.75/x
3. Step 3: Cross multiply
   90.89x = 136.28 × 42.75
4. Step 4: Simplify right side
   90.89x = 5,825.76
5. Step 5: Solve for x
   x = 5,825.76/90.89
6. Step 6: Final answer
   x = 64.10