Finding the Fourth Proportional to 28.10, 42.18 and 21.32

Step by Step Solution

1. Step 1: Write the proportion equation
   28.10 : 42.18 = 21.32 : x
2. Step 2: Convert to fraction form
   28.10/42.18 = 21.32/x
3. Step 3: Cross multiply
   28.10x = 42.18 × 21.32
4. Step 4: Simplify right side
   28.10x = 899.28
5. Step 5: Solve for x
   x = 899.28/28.10
6. Step 6: Final answer
   x = 32.00