Finding the Fourth Proportional to 42.26, 63.42 and 28.55

Step by Step Solution

1. Step 1: Write the proportion equation
   42.26 : 63.42 = 28.55 : x
2. Step 2: Convert to fraction form
   42.26/63.42 = 28.55/x
3. Step 3: Cross multiply
   42.26x = 63.42 × 28.55
4. Step 4: Simplify right side
   42.26x = 1,810.32
5. Step 5: Solve for x
   x = 1,810.32/42.26
6. Step 6: Final answer
   x = 42.84