Finding the Fourth Proportional to 1,656.57, 2,478.66 and 1,638.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,656.57 : 2,478.66 = 1,638.12 : x
2. Step 2: Convert to fraction form
   1,656.57/2,478.66 = 1,638.12/x
3. Step 3: Cross multiply
   1,656.57x = 2,478.66 × 1,638.12
4. Step 4: Simplify right side
   1,656.57x = 4,060,342.52
5. Step 5: Solve for x
   x = 4,060,342.52/1,656.57
6. Step 6: Final answer
   x = 2,451.05