Finding the Fourth Proportional to 1,384.37, 1,910.64 and 860.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,384.37 : 1,910.64 = 860.57 : x
2. Step 2: Convert to fraction form
   1,384.37/1,910.64 = 860.57/x
3. Step 3: Cross multiply
   1,384.37x = 1,910.64 × 860.57
4. Step 4: Simplify right side
   1,384.37x = 1,644,239.46
5. Step 5: Solve for x
   x = 1,644,239.46/1,384.37
6. Step 6: Final answer
   x = 1,187.72