Finding the Fourth Proportional to 1,559.31, 2,151.92 and 860.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,559.31 : 2,151.92 = 860.69 : x
2. Step 2: Convert to fraction form
   1,559.31/2,151.92 = 860.69/x
3. Step 3: Cross multiply
   1,559.31x = 2,151.92 × 860.69
4. Step 4: Simplify right side
   1,559.31x = 1,852,136.02
5. Step 5: Solve for x
   x = 1,852,136.02/1,559.31
6. Step 6: Final answer
   x = 1,187.79