Finding the Fourth Proportional to 1,635.72, 2,439.76 and 1,389.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,635.72 : 2,439.76 = 1,389.48 : x
2. Step 2: Convert to fraction form
   1,635.72/2,439.76 = 1,389.48/x
3. Step 3: Cross multiply
   1,635.72x = 2,439.76 × 1,389.48
4. Step 4: Simplify right side
   1,635.72x = 3,389,997.72
5. Step 5: Solve for x
   x = 3,389,997.72/1,635.72
6. Step 6: Final answer
   x = 2,072.48