Finding the Fourth Proportional to 2,313.61, 3,471.78 and 853.79

Step by Step Solution

1. Step 1: Write the proportion equation
   2,313.61 : 3,471.78 = 853.79 : x
2. Step 2: Convert to fraction form
   2,313.61/3,471.78 = 853.79/x
3. Step 3: Cross multiply
   2,313.61x = 3,471.78 × 853.79
4. Step 4: Simplify right side
   2,313.61x = 2,964,156.89
5. Step 5: Solve for x
   x = 2,964,156.89/2,313.61
6. Step 6: Final answer
   x = 1,281.18