Finding the Fourth Proportional to 28.32, 42.20 and 28.10

Step by Step Solution

1. Step 1: Write the proportion equation
   28.32 : 42.20 = 28.10 : x
2. Step 2: Convert to fraction form
   28.32/42.20 = 28.10/x
3. Step 3: Cross multiply
   28.32x = 42.20 × 28.10
4. Step 4: Simplify right side
   28.32x = 1,185.82
5. Step 5: Solve for x
   x = 1,185.82/28.32
6. Step 6: Final answer
   x = 41.87