Finding the Fourth Proportional to 5,100.78, 7,649.55 and 2,178.30

Step by Step Solution

1. Step 1: Write the proportion equation
   5,100.78 : 7,649.55 = 2,178.30 : x
2. Step 2: Convert to fraction form
   5,100.78/7,649.55 = 2,178.30/x
3. Step 3: Cross multiply
   5,100.78x = 7,649.55 × 2,178.30
4. Step 4: Simplify right side
   5,100.78x = 16,663,014.77
5. Step 5: Solve for x
   x = 16,663,014.77/5,100.78
6. Step 6: Final answer
   x = 3,266.76