Finding the Fourth Proportional to 8,100.78, 12,152.86 and 3,420.80

Step by Step Solution

1. Step 1: Write the proportion equation
   8,100.78 : 12,152.86 = 3,420.80 : x
2. Step 2: Convert to fraction form
   8,100.78/12,152.86 = 3,420.80/x
3. Step 3: Cross multiply
   8,100.78x = 12,152.86 × 3,420.80
4. Step 4: Simplify right side
   8,100.78x = 41,572,479.74
5. Step 5: Solve for x
   x = 41,572,479.74/8,100.78
6. Step 6: Final answer
   x = 5,131.91