Finding the Fourth Proportional to 90.58, 135.83 and 42.50

Step by Step Solution

1. Step 1: Write the proportion equation
   90.58 : 135.83 = 42.50 : x
2. Step 2: Convert to fraction form
   90.58/135.83 = 42.50/x
3. Step 3: Cross multiply
   90.58x = 135.83 × 42.50
4. Step 4: Simplify right side
   90.58x = 5,772.78
5. Step 5: Solve for x
   x = 5,772.78/90.58
6. Step 6: Final answer
   x = 63.73