Finding the Fourth Proportional to 1,356.71, 1,871.52 and 859.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,356.71 : 1,871.52 = 859.15 : x
2. Step 2: Convert to fraction form
   1,356.71/1,871.52 = 859.15/x
3. Step 3: Cross multiply
   1,356.71x = 1,871.52 × 859.15
4. Step 4: Simplify right side
   1,356.71x = 1,607,907.05
5. Step 5: Solve for x
   x = 1,607,907.05/1,356.71
6. Step 6: Final answer
   x = 1,185.15