Finding the Fourth Proportional to 1,780.69, 2,457.39 and 994.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,780.69 : 2,457.39 = 994.78 : x
2. Step 2: Convert to fraction form
   1,780.69/2,457.39 = 994.78/x
3. Step 3: Cross multiply
   1,780.69x = 2,457.39 × 994.78
4. Step 4: Simplify right side
   1,780.69x = 2,444,562.42
5. Step 5: Solve for x
   x = 2,444,562.42/1,780.69
6. Step 6: Final answer
   x = 1,372.82