Finding the Fourth Proportional to 2,109.40, 3,162.45 and 1,287.52

Step by Step Solution

1. Step 1: Write the proportion equation
   2,109.40 : 3,162.45 = 1,287.52 : x
2. Step 2: Convert to fraction form
   2,109.40/3,162.45 = 1,287.52/x
3. Step 3: Cross multiply
   2,109.40x = 3,162.45 × 1,287.52
4. Step 4: Simplify right side
   2,109.40x = 4,071,717.62
5. Step 5: Solve for x
   x = 4,071,717.62/2,109.40
6. Step 6: Final answer
   x = 1,930.27