Finding the Fourth Proportional to 2,171.53, 2,996.72 and 1,287.39

Step by Step Solution

1. Step 1: Write the proportion equation
   2,171.53 : 2,996.72 = 1,287.39 : x
2. Step 2: Convert to fraction form
   2,171.53/2,996.72 = 1,287.39/x
3. Step 3: Cross multiply
   2,171.53x = 2,996.72 × 1,287.39
4. Step 4: Simplify right side
   2,171.53x = 3,857,960.61
5. Step 5: Solve for x
   x = 3,857,960.61/2,171.53
6. Step 6: Final answer
   x = 1,776.61