Finding the Fourth Proportional to 1,780.10, 2,456.56 and 994.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,780.10 : 2,456.56 = 994.20 : x
2. Step 2: Convert to fraction form
   1,780.10/2,456.56 = 994.20/x
3. Step 3: Cross multiply
   1,780.10x = 2,456.56 × 994.20
4. Step 4: Simplify right side
   1,780.10x = 2,442,311.95
5. Step 5: Solve for x
   x = 2,442,311.95/1,780.10
6. Step 6: Final answer
   x = 1,372.01