Finding the Fourth Proportional to 1,320.09, 1,822.17 and 878.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,320.09 : 1,822.17 = 878.10 : x
2. Step 2: Convert to fraction form
   1,320.09/1,822.17 = 878.10/x
3. Step 3: Cross multiply
   1,320.09x = 1,822.17 × 878.10
4. Step 4: Simplify right side
   1,320.09x = 1,600,047.48
5. Step 5: Solve for x
   x = 1,600,047.48/1,320.09
6. Step 6: Final answer
   x = 1,212.07