Finding the Fourth Proportional to 12,870.04, 19,300.20 and 5,478

Step by Step Solution

1. Step 1: Write the proportion equation
   12,870.04 : 19,300.20 = 5,478 : x
2. Step 2: Convert to fraction form
   12,870.04/19,300.20 = 5,478/x
3. Step 3: Cross multiply
   12,870.04x = 19,300.20 × 5,478
4. Step 4: Simplify right side
   12,870.04x = 105,726,495.60
5. Step 5: Solve for x
   x = 105,726,495.60/12,870.04
6. Step 6: Final answer
   x = 8,214.93