Finding the Fourth Proportional to 90.98, 136.53 and 42.86

Step by Step Solution

1. Step 1: Write the proportion equation
   90.98 : 136.53 = 42.86 : x
2. Step 2: Convert to fraction form
   90.98/136.53 = 42.86/x
3. Step 3: Cross multiply
   90.98x = 136.53 × 42.86
4. Step 4: Simplify right side
   90.98x = 5,851.68
5. Step 5: Solve for x
   x = 5,851.68/90.98
6. Step 6: Final answer
   x = 64.32