Finding the Fourth Proportional to 42.47, 58.56 and 31.55

Step by Step Solution

1. Step 1: Write the proportion equation
   42.47 : 58.56 = 31.55 : x
2. Step 2: Convert to fraction form
   42.47/58.56 = 31.55/x
3. Step 3: Cross multiply
   42.47x = 58.56 × 31.55
4. Step 4: Simplify right side
   42.47x = 1,847.41
5. Step 5: Solve for x
   x = 1,847.41/42.47
6. Step 6: Final answer
   x = 43.50