Finding the Fourth Proportional to 2,109.78, 3,165.28 and 876.96

Step by Step Solution

1. Step 1: Write the proportion equation
   2,109.78 : 3,165.28 = 876.96 : x
2. Step 2: Convert to fraction form
   2,109.78/3,165.28 = 876.96/x
3. Step 3: Cross multiply
   2,109.78x = 3,165.28 × 876.96
4. Step 4: Simplify right side
   2,109.78x = 2,775,823.95
5. Step 5: Solve for x
   x = 2,775,823.95/2,109.78
6. Step 6: Final answer
   x = 1,315.69