Finding the Fourth Proportional to 1,448.78, 2,171.55 and 872.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,448.78 : 2,171.55 = 872.06 : x
2. Step 2: Convert to fraction form
   1,448.78/2,171.55 = 872.06/x
3. Step 3: Cross multiply
   1,448.78x = 2,171.55 × 872.06
4. Step 4: Simplify right side
   1,448.78x = 1,893,721.89
5. Step 5: Solve for x
   x = 1,893,721.89/1,448.78
6. Step 6: Final answer
   x = 1,307.11