Finding the Fourth Proportional to 2,015.89, 2,780.73 and 1,218.65

Step by Step Solution

1. Step 1: Write the proportion equation
   2,015.89 : 2,780.73 = 1,218.65 : x
2. Step 2: Convert to fraction form
   2,015.89/2,780.73 = 1,218.65/x
3. Step 3: Cross multiply
   2,015.89x = 2,780.73 × 1,218.65
4. Step 4: Simplify right side
   2,015.89x = 3,388,722.71
5. Step 5: Solve for x
   x = 3,388,722.71/2,015.89
6. Step 6: Final answer
   x = 1,681.01