Finding the Fourth Proportional to 2,172.78, 2,998.74 and 1,228.86

Step by Step Solution

1. Step 1: Write the proportion equation
   2,172.78 : 2,998.74 = 1,228.86 : x
2. Step 2: Convert to fraction form
   2,172.78/2,998.74 = 1,228.86/x
3. Step 3: Cross multiply
   2,172.78x = 2,998.74 × 1,228.86
4. Step 4: Simplify right side
   2,172.78x = 3,685,016.64
5. Step 5: Solve for x
   x = 3,685,016.64/2,172.78
6. Step 6: Final answer
   x = 1,696.00