Finding the Fourth Proportional to 2,115.48, 3,172.41 and 1,248.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,115.48 : 3,172.41 = 1,248.78 : x
2. Step 2: Convert to fraction form
   2,115.48/3,172.41 = 1,248.78/x
3. Step 3: Cross multiply
   2,115.48x = 3,172.41 × 1,248.78
4. Step 4: Simplify right side
   2,115.48x = 3,961,642.16
5. Step 5: Solve for x
   x = 3,961,642.16/2,115.48
6. Step 6: Final answer
   x = 1,872.69