Finding the Fourth Proportional to 1,663.08, 2,487.90 and 1,389.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,663.08 : 2,487.90 = 1,389.72 : x
2. Step 2: Convert to fraction form
   1,663.08/2,487.90 = 1,389.72/x
3. Step 3: Cross multiply
   1,663.08x = 2,487.90 × 1,389.72
4. Step 4: Simplify right side
   1,663.08x = 3,457,484.39
5. Step 5: Solve for x
   x = 3,457,484.39/1,663.08
6. Step 6: Final answer
   x = 2,078.96