Finding the Fourth Proportional to 1,357.40, 1,872.86 and 860.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,357.40 : 1,872.86 = 860.61 : x
2. Step 2: Convert to fraction form
   1,357.40/1,872.86 = 860.61/x
3. Step 3: Cross multiply
   1,357.40x = 1,872.86 × 860.61
4. Step 4: Simplify right side
   1,357.40x = 1,611,802.04
5. Step 5: Solve for x
   x = 1,611,802.04/1,357.40
6. Step 6: Final answer
   x = 1,187.42