Finding the Fourth Proportional to 1,507.72, 2,080.36 and 878.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,507.72 : 2,080.36 = 878.12 : x
2. Step 2: Convert to fraction form
   1,507.72/2,080.36 = 878.12/x
3. Step 3: Cross multiply
   1,507.72x = 2,080.36 × 878.12
4. Step 4: Simplify right side
   1,507.72x = 1,826,805.72
5. Step 5: Solve for x
   x = 1,826,805.72/1,507.72
6. Step 6: Final answer
   x = 1,211.63