Finding the Fourth Proportional to 82.90, 124.15 and 42.22

Step by Step Solution

1. Step 1: Write the proportion equation
   82.90 : 124.15 = 42.22 : x
2. Step 2: Convert to fraction form
   82.90/124.15 = 42.22/x
3. Step 3: Cross multiply
   82.90x = 124.15 × 42.22
4. Step 4: Simplify right side
   82.90x = 5,241.61
5. Step 5: Solve for x
   x = 5,241.61/82.90
6. Step 6: Final answer
   x = 63.23