Finding the Fourth Proportional to 2,543.72, 3,815.64 and 1,389.47

Step by Step Solution

1. Step 1: Write the proportion equation
   2,543.72 : 3,815.64 = 1,389.47 : x
2. Step 2: Convert to fraction form
   2,543.72/3,815.64 = 1,389.47/x
3. Step 3: Cross multiply
   2,543.72x = 3,815.64 × 1,389.47
4. Step 4: Simplify right side
   2,543.72x = 5,301,698.23
5. Step 5: Solve for x
   x = 5,301,698.23/2,543.72
6. Step 6: Final answer
   x = 2,084.23