Finding the Fourth Proportional to 87.82, 131.82 and 42.20

Step by Step Solution

1. Step 1: Write the proportion equation
   87.82 : 131.82 = 42.20 : x
2. Step 2: Convert to fraction form
   87.82/131.82 = 42.20/x
3. Step 3: Cross multiply
   87.82x = 131.82 × 42.20
4. Step 4: Simplify right side
   87.82x = 5,563.02
5. Step 5: Solve for x
   x = 5,563.02/87.82
6. Step 6: Final answer
   x = 63.34