Finding the Fourth Proportional to 112.50, 168.50 and 82.12

Step by Step Solution

1. Step 1: Write the proportion equation
   112.50 : 168.50 = 82.12 : x
2. Step 2: Convert to fraction form
   112.50/168.50 = 82.12/x
3. Step 3: Cross multiply
   112.50x = 168.50 × 82.12
4. Step 4: Simplify right side
   112.50x = 13,837.22
5. Step 5: Solve for x
   x = 13,837.22/112.50
6. Step 6: Final answer
   x = 123.00