Finding the Fourth Proportional to 2,399.90, 3,599.28 and 918.81

Step by Step Solution

1. Step 1: Write the proportion equation
   2,399.90 : 3,599.28 = 918.81 : x
2. Step 2: Convert to fraction form
   2,399.90/3,599.28 = 918.81/x
3. Step 3: Cross multiply
   2,399.90x = 3,599.28 × 918.81
4. Step 4: Simplify right side
   2,399.90x = 3,307,054.46
5. Step 5: Solve for x
   x = 3,307,054.46/2,399.90
6. Step 6: Final answer
   x = 1,378.00