Finding the Fourth Proportional to 2,145.27, 3,215.85 and 828.06

Step by Step Solution

1. Step 1: Write the proportion equation
   2,145.27 : 3,215.85 = 828.06 : x
2. Step 2: Convert to fraction form
   2,145.27/3,215.85 = 828.06/x
3. Step 3: Cross multiply
   2,145.27x = 3,215.85 × 828.06
4. Step 4: Simplify right side
   2,145.27x = 2,662,901.59
5. Step 5: Solve for x
   x = 2,662,901.59/2,145.27
6. Step 6: Final answer
   x = 1,241.29