Finding the Fourth Proportional to 1,665.12, 2,496.06 and 843.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,665.12 : 2,496.06 = 843.78 : x
2. Step 2: Convert to fraction form
   1,665.12/2,496.06 = 843.78/x
3. Step 3: Cross multiply
   1,665.12x = 2,496.06 × 843.78
4. Step 4: Simplify right side
   1,665.12x = 2,106,125.51
5. Step 5: Solve for x
   x = 2,106,125.51/1,665.12
6. Step 6: Final answer
   x = 1,264.85