Finding the Fourth Proportional to 28.37, 42.47 and 18.72

Step by Step Solution

1. Step 1: Write the proportion equation
   28.37 : 42.47 = 18.72 : x
2. Step 2: Convert to fraction form
   28.37/42.47 = 18.72/x
3. Step 3: Cross multiply
   28.37x = 42.47 × 18.72
4. Step 4: Simplify right side
   28.37x = 795.04
5. Step 5: Solve for x
   x = 795.04/28.37
6. Step 6: Final answer
   x = 28.02