Finding the Fourth Proportional to 2,017.84, 2,784.64 and 1,221.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,017.84 : 2,784.64 = 1,221.15 : x
2. Step 2: Convert to fraction form
   2,017.84/2,784.64 = 1,221.15/x
3. Step 3: Cross multiply
   2,017.84x = 2,784.64 × 1,221.15
4. Step 4: Simplify right side
   2,017.84x = 3,400,466.70
5. Step 5: Solve for x
   x = 3,400,466.70/2,017.84
6. Step 6: Final answer
   x = 1,685.20