Finding the Fourth Proportional to 1,385.69, 1,909.85 and 1,012.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.69 : 1,909.85 = 1,012.05 : x
2. Step 2: Convert to fraction form
   1,385.69/1,909.85 = 1,012.05/x
3. Step 3: Cross multiply
   1,385.69x = 1,909.85 × 1,012.05
4. Step 4: Simplify right side
   1,385.69x = 1,932,858.63
5. Step 5: Solve for x
   x = 1,932,858.63/1,385.69
6. Step 6: Final answer
   x = 1,394.88