Finding the Fourth Proportional to 3,978.86, 5,490.74 and 2,210.45

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.86 : 5,490.74 = 2,210.45 : x
2. Step 2: Convert to fraction form
   3,978.86/5,490.74 = 2,210.45/x
3. Step 3: Cross multiply
   3,978.86x = 5,490.74 × 2,210.45
4. Step 4: Simplify right side
   3,978.86x = 12,136,984.31
5. Step 5: Solve for x
   x = 12,136,984.31/3,978.86
6. Step 6: Final answer
   x = 3,050.37