Finding the Fourth Proportional to 12,870.50, 19,309 and 3,636.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,870.50 : 19,309 = 3,636.50 : x
2. Step 2: Convert to fraction form
   12,870.50/19,309 = 3,636.50/x
3. Step 3: Cross multiply
   12,870.50x = 19,309 × 3,636.50
4. Step 4: Simplify right side
   12,870.50x = 70,217,178.50
5. Step 5: Solve for x
   x = 70,217,178.50/12,870.50
6. Step 6: Final answer
   x = 5,455.67