Finding the Fourth Proportional to 1,439.29, 1,986.69 and 1,066.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,439.29 : 1,986.69 = 1,066.15 : x
2. Step 2: Convert to fraction form
   1,439.29/1,986.69 = 1,066.15/x
3. Step 3: Cross multiply
   1,439.29x = 1,986.69 × 1,066.15
4. Step 4: Simplify right side
   1,439.29x = 2,118,109.54
5. Step 5: Solve for x
   x = 2,118,109.54/1,439.29
6. Step 6: Final answer
   x = 1,471.64