Finding the Fourth Proportional to 1,049.31, 1,571.72 and 853.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,049.31 : 1,571.72 = 853.38 : x
2. Step 2: Convert to fraction form
   1,049.31/1,571.72 = 853.38/x
3. Step 3: Cross multiply
   1,049.31x = 1,571.72 × 853.38
4. Step 4: Simplify right side
   1,049.31x = 1,341,270.15
5. Step 5: Solve for x
   x = 1,341,270.15/1,049.31
6. Step 6: Final answer
   x = 1,278.24