Finding the Fourth Proportional to 1,381.25, 2,066.99 and 860.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,381.25 : 2,066.99 = 860.83 : x
2. Step 2: Convert to fraction form
   1,381.25/2,066.99 = 860.83/x
3. Step 3: Cross multiply
   1,381.25x = 2,066.99 × 860.83
4. Step 4: Simplify right side
   1,381.25x = 1,779,317.53
5. Step 5: Solve for x
   x = 1,779,317.53/1,381.25
6. Step 6: Final answer
   x = 1,288.19