Finding the Fourth Proportional to 2,070.64, 2,857.56 and 1,139.12

Step by Step Solution

1. Step 1: Write the proportion equation
   2,070.64 : 2,857.56 = 1,139.12 : x
2. Step 2: Convert to fraction form
   2,070.64/2,857.56 = 1,139.12/x
3. Step 3: Cross multiply
   2,070.64x = 2,857.56 × 1,139.12
4. Step 4: Simplify right side
   2,070.64x = 3,255,103.75
5. Step 5: Solve for x
   x = 3,255,103.75/2,070.64
6. Step 6: Final answer
   x = 1,572.03