Finding the Fourth Proportional to 2,017.80, 3,025.71 and 921.60

Step by Step Solution

1. Step 1: Write the proportion equation
   2,017.80 : 3,025.71 = 921.60 : x
2. Step 2: Convert to fraction form
   2,017.80/3,025.71 = 921.60/x
3. Step 3: Cross multiply
   2,017.80x = 3,025.71 × 921.60
4. Step 4: Simplify right side
   2,017.80x = 2,788,494.34
5. Step 5: Solve for x
   x = 2,788,494.34/2,017.80
6. Step 6: Final answer
   x = 1,381.95