Finding the Fourth Proportional to 1,674.86, 2,513.91 and 809.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,674.86 : 2,513.91 = 809.78 : x
2. Step 2: Convert to fraction form
   1,674.86/2,513.91 = 809.78/x
3. Step 3: Cross multiply
   1,674.86x = 2,513.91 × 809.78
4. Step 4: Simplify right side
   1,674.86x = 2,035,714.04
5. Step 5: Solve for x
   x = 2,035,714.04/1,674.86
6. Step 6: Final answer
   x = 1,215.45