Finding the Fourth Proportional to 2,002.80, 2,764.60 and 1,216.88

Step by Step Solution

1. Step 1: Write the proportion equation
   2,002.80 : 2,764.60 = 1,216.88 : x
2. Step 2: Convert to fraction form
   2,002.80/2,764.60 = 1,216.88/x
3. Step 3: Cross multiply
   2,002.80x = 2,764.60 × 1,216.88
4. Step 4: Simplify right side
   2,002.80x = 3,364,186.45
5. Step 5: Solve for x
   x = 3,364,186.45/2,002.80
6. Step 6: Final answer
   x = 1,679.74