Finding the Fourth Proportional to 1,280.21, 1,918.69 and 868.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,280.21 : 1,918.69 = 868.32 : x
2. Step 2: Convert to fraction form
   1,280.21/1,918.69 = 868.32/x
3. Step 3: Cross multiply
   1,280.21x = 1,918.69 × 868.32
4. Step 4: Simplify right side
   1,280.21x = 1,666,034.73
5. Step 5: Solve for x
   x = 1,666,034.73/1,280.21
6. Step 6: Final answer
   x = 1,301.38