Finding the Fourth Proportional to 2,820.67, 4,231.16 and 872.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,820.67 : 4,231.16 = 872.72 : x
2. Step 2: Convert to fraction form
   2,820.67/4,231.16 = 872.72/x
3. Step 3: Cross multiply
   2,820.67x = 4,231.16 × 872.72
4. Step 4: Simplify right side
   2,820.67x = 3,692,611.58
5. Step 5: Solve for x
   x = 3,692,611.58/2,820.67
6. Step 6: Final answer
   x = 1,309.13