Finding the Fourth Proportional to 2,101.28, 2,900.72 and 1,216.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,101.28 : 2,900.72 = 1,216.89 : x
2. Step 2: Convert to fraction form
   2,101.28/2,900.72 = 1,216.89/x
3. Step 3: Cross multiply
   2,101.28x = 2,900.72 × 1,216.89
4. Step 4: Simplify right side
   2,101.28x = 3,529,860.20
5. Step 5: Solve for x
   x = 3,529,860.20/2,101.28
6. Step 6: Final answer
   x = 1,679.87