Finding the Fourth Proportional to 28.31, 42.12 and 28.22

Step by Step Solution

1. Step 1: Write the proportion equation
   28.31 : 42.12 = 28.22 : x
2. Step 2: Convert to fraction form
   28.31/42.12 = 28.22/x
3. Step 3: Cross multiply
   28.31x = 42.12 × 28.22
4. Step 4: Simplify right side
   28.31x = 1,188.63
5. Step 5: Solve for x
   x = 1,188.63/28.31
6. Step 6: Final answer
   x = 41.99