Finding the Fourth Proportional to 2,057.18, 2,838.69 and 1,172.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,057.18 : 2,838.69 = 1,172.90 : x
2. Step 2: Convert to fraction form
   2,057.18/2,838.69 = 1,172.90/x
3. Step 3: Cross multiply
   2,057.18x = 2,838.69 × 1,172.90
4. Step 4: Simplify right side
   2,057.18x = 3,329,499.50
5. Step 5: Solve for x
   x = 3,329,499.50/2,057.18
6. Step 6: Final answer
   x = 1,618.48