Finding the Fourth Proportional to 2,642.78, 3,960.68 and 1,407.53

Step by Step Solution

1. Step 1: Write the proportion equation
   2,642.78 : 3,960.68 = 1,407.53 : x
2. Step 2: Convert to fraction form
   2,642.78/3,960.68 = 1,407.53/x
3. Step 3: Cross multiply
   2,642.78x = 3,960.68 × 1,407.53
4. Step 4: Simplify right side
   2,642.78x = 5,574,778.78
5. Step 5: Solve for x
   x = 5,574,778.78/2,642.78
6. Step 6: Final answer
   x = 2,109.44