Finding the Fourth Proportional to 2,213.91, 3,319.38 and 825.57

Step by Step Solution

1. Step 1: Write the proportion equation
   2,213.91 : 3,319.38 = 825.57 : x
2. Step 2: Convert to fraction form
   2,213.91/3,319.38 = 825.57/x
3. Step 3: Cross multiply
   2,213.91x = 3,319.38 × 825.57
4. Step 4: Simplify right side
   2,213.91x = 2,740,380.55
5. Step 5: Solve for x
   x = 2,740,380.55/2,213.91
6. Step 6: Final answer
   x = 1,237.80