Finding the Fourth Proportional to 2,660.49, 3,990.77 and 1,017.12

Step by Step Solution

1. Step 1: Write the proportion equation
   2,660.49 : 3,990.77 = 1,017.12 : x
2. Step 2: Convert to fraction form
   2,660.49/3,990.77 = 1,017.12/x
3. Step 3: Cross multiply
   2,660.49x = 3,990.77 × 1,017.12
4. Step 4: Simplify right side
   2,660.49x = 4,059,094.53
5. Step 5: Solve for x
   x = 4,059,094.53/2,660.49
6. Step 6: Final answer
   x = 1,525.69