Finding the Fourth Proportional to 1,661.58, 2,491.81 and 839.33

Step by Step Solution

1. Step 1: Write the proportion equation
   1,661.58 : 2,491.81 = 839.33 : x
2. Step 2: Convert to fraction form
   1,661.58/2,491.81 = 839.33/x
3. Step 3: Cross multiply
   1,661.58x = 2,491.81 × 839.33
4. Step 4: Simplify right side
   1,661.58x = 2,091,450.89
5. Step 5: Solve for x
   x = 2,091,450.89/1,661.58
6. Step 6: Final answer
   x = 1,258.71