Finding the Fourth Proportional to 1,878.09, 2,590.89 and 1,215.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,878.09 : 2,590.89 = 1,215.15 : x
2. Step 2: Convert to fraction form
   1,878.09/2,590.89 = 1,215.15/x
3. Step 3: Cross multiply
   1,878.09x = 2,590.89 × 1,215.15
4. Step 4: Simplify right side
   1,878.09x = 3,148,320.28
5. Step 5: Solve for x
   x = 3,148,320.28/1,878.09
6. Step 6: Final answer
   x = 1,676.34