Finding the Fourth Proportional to 1,507.31, 2,080.31 and 878.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,507.31 : 2,080.31 = 878.21 : x
2. Step 2: Convert to fraction form
   1,507.31/2,080.31 = 878.21/x
3. Step 3: Cross multiply
   1,507.31x = 2,080.31 × 878.21
4. Step 4: Simplify right side
   1,507.31x = 1,826,934.25
5. Step 5: Solve for x
   x = 1,826,934.25/1,507.31
6. Step 6: Final answer
   x = 1,212.05