Finding the Fourth Proportional to 1,665.20, 2,488.06 and 1,665.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,665.20 : 2,488.06 = 1,665.20 : x
2. Step 2: Convert to fraction form
   1,665.20/2,488.06 = 1,665.20/x
3. Step 3: Cross multiply
   1,665.20x = 2,488.06 × 1,665.20
4. Step 4: Simplify right side
   1,665.20x = 4,143,117.51
5. Step 5: Solve for x
   x = 4,143,117.51/1,665.20
6. Step 6: Final answer
   x = 2,488.06