Finding the Fourth Proportional to 1,780.40, 2,456.91 and 994.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,780.40 : 2,456.91 = 994.43 : x
2. Step 2: Convert to fraction form
   1,780.40/2,456.91 = 994.43/x
3. Step 3: Cross multiply
   1,780.40x = 2,456.91 × 994.43
4. Step 4: Simplify right side
   1,780.40x = 2,443,212.73
5. Step 5: Solve for x
   x = 2,443,212.73/1,780.40
6. Step 6: Final answer
   x = 1,372.29