Finding the Fourth Proportional to 2,100.81, 2,898.78 and 1,216.69

Step by Step Solution

1. Step 1: Write the proportion equation
   2,100.81 : 2,898.78 = 1,216.69 : x
2. Step 2: Convert to fraction form
   2,100.81/2,898.78 = 1,216.69/x
3. Step 3: Cross multiply
   2,100.81x = 2,898.78 × 1,216.69
4. Step 4: Simplify right side
   2,100.81x = 3,526,910.55
5. Step 5: Solve for x
   x = 3,526,910.55/2,100.81
6. Step 6: Final answer
   x = 1,678.83