Finding the Fourth Proportional to 1,385.05, 1,910.94 and 853.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.05 : 1,910.94 = 853.38 : x
2. Step 2: Convert to fraction form
   1,385.05/1,910.94 = 853.38/x
3. Step 3: Cross multiply
   1,385.05x = 1,910.94 × 853.38
4. Step 4: Simplify right side
   1,385.05x = 1,630,757.98
5. Step 5: Solve for x
   x = 1,630,757.98/1,385.05
6. Step 6: Final answer
   x = 1,177.40