Finding the Fourth Proportional to 12,870.54, 19,300.95 and 5,478.48

Step by Step Solution

1. Step 1: Write the proportion equation
   12,870.54 : 19,300.95 = 5,478.48 : x
2. Step 2: Convert to fraction form
   12,870.54/19,300.95 = 5,478.48/x
3. Step 3: Cross multiply
   12,870.54x = 19,300.95 × 5,478.48
4. Step 4: Simplify right side
   12,870.54x = 105,739,868.56
5. Step 5: Solve for x
   x = 105,739,868.56/12,870.54
6. Step 6: Final answer
   x = 8,215.65