Finding the Fourth Proportional to 2,860.48, 3,948.78 and 2,021.86

Step by Step Solution

1. Step 1: Write the proportion equation
   2,860.48 : 3,948.78 = 2,021.86 : x
2. Step 2: Convert to fraction form
   2,860.48/3,948.78 = 2,021.86/x
3. Step 3: Cross multiply
   2,860.48x = 3,948.78 × 2,021.86
4. Step 4: Simplify right side
   2,860.48x = 7,983,880.33
5. Step 5: Solve for x
   x = 7,983,880.33/2,860.48
6. Step 6: Final answer
   x = 2,791.10