Finding the Fourth Proportional to 1,772.10, 2,654.55 and 820.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,772.10 : 2,654.55 = 820.91 : x
2. Step 2: Convert to fraction form
   1,772.10/2,654.55 = 820.91/x
3. Step 3: Cross multiply
   1,772.10x = 2,654.55 × 820.91
4. Step 4: Simplify right side
   1,772.10x = 2,179,133.37
5. Step 5: Solve for x
   x = 2,179,133.37/1,772.10
6. Step 6: Final answer
   x = 1,229.69