Finding the Fourth Proportional to 28.18, 42.56 and 28.18

Step by Step Solution

1. Step 1: Write the proportion equation
   28.18 : 42.56 = 28.18 : x
2. Step 2: Convert to fraction form
   28.18/42.56 = 28.18/x
3. Step 3: Cross multiply
   28.18x = 42.56 × 28.18
4. Step 4: Simplify right side
   28.18x = 1,199.30
5. Step 5: Solve for x
   x = 1,199.30/28.18
6. Step 6: Final answer
   x = 42.56