Finding the Fourth Proportional to 2,709.81, 4,065.30 and 860.70

Step by Step Solution

1. Step 1: Write the proportion equation
   2,709.81 : 4,065.30 = 860.70 : x
2. Step 2: Convert to fraction form
   2,709.81/4,065.30 = 860.70/x
3. Step 3: Cross multiply
   2,709.81x = 4,065.30 × 860.70
4. Step 4: Simplify right side
   2,709.81x = 3,499,003.71
5. Step 5: Solve for x
   x = 3,499,003.71/2,709.81
6. Step 6: Final answer
   x = 1,291.24