Finding the Fourth Proportional to 1,688.72, 2,546.59 and 1,665.62

Step by Step Solution

1. Step 1: Write the proportion equation
   1,688.72 : 2,546.59 = 1,665.62 : x
2. Step 2: Convert to fraction form
   1,688.72/2,546.59 = 1,665.62/x
3. Step 3: Cross multiply
   1,688.72x = 2,546.59 × 1,665.62
4. Step 4: Simplify right side
   1,688.72x = 4,241,642.91
5. Step 5: Solve for x
   x = 4,241,642.91/1,688.72
6. Step 6: Final answer
   x = 2,511.75