Finding the Fourth Proportional to 2,218.59, 3,328.67 and 985.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,218.59 : 3,328.67 = 985.89 : x
2. Step 2: Convert to fraction form
   2,218.59/3,328.67 = 985.89/x
3. Step 3: Cross multiply
   2,218.59x = 3,328.67 × 985.89
4. Step 4: Simplify right side
   2,218.59x = 3,281,704.93
5. Step 5: Solve for x
   x = 3,281,704.93/2,218.59
6. Step 6: Final answer
   x = 1,479.18