Finding the Fourth Proportional to 42,450, 63,684.20 and 12,870.10

Step by Step Solution

1. Step 1: Write the proportion equation
   42,450 : 63,684.20 = 12,870.10 : x
2. Step 2: Convert to fraction form
   42,450/63,684.20 = 12,870.10/x
3. Step 3: Cross multiply
   42,450x = 63,684.20 × 12,870.10
4. Step 4: Simplify right side
   42,450x = 819,622,022.42
5. Step 5: Solve for x
   x = 819,622,022.42/42,450
6. Step 6: Final answer
   x = 19,307.94