Finding the Fourth Proportional to 3,785.98, 5,678.94 and 1,320.79

Step by Step Solution

1. Step 1: Write the proportion equation
   3,785.98 : 5,678.94 = 1,320.79 : x
2. Step 2: Convert to fraction form
   3,785.98/5,678.94 = 1,320.79/x
3. Step 3: Cross multiply
   3,785.98x = 5,678.94 × 1,320.79
4. Step 4: Simplify right side
   3,785.98x = 7,500,687.16
5. Step 5: Solve for x
   x = 7,500,687.16/3,785.98
6. Step 6: Final answer
   x = 1,981.17