Finding the Fourth Proportional to 2,091.25, 2,885.90 and 1,207.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,091.25 : 2,885.90 = 1,207.20 : x
2. Step 2: Convert to fraction form
   2,091.25/2,885.90 = 1,207.20/x
3. Step 3: Cross multiply
   2,091.25x = 2,885.90 × 1,207.20
4. Step 4: Simplify right side
   2,091.25x = 3,483,863.27
5. Step 5: Solve for x
   x = 3,483,863.27/2,091.25
6. Step 6: Final answer
   x = 1,665.92