Finding the Fourth Proportional to 13,172.27, 18,179.89 and 7,870.21

Step by Step Solution

1. Step 1: Write the proportion equation
   13,172.27 : 18,179.89 = 7,870.21 : x
2. Step 2: Convert to fraction form
   13,172.27/18,179.89 = 7,870.21/x
3. Step 3: Cross multiply
   13,172.27x = 18,179.89 × 7,870.21
4. Step 4: Simplify right side
   13,172.27x = 143,079,486.95
5. Step 5: Solve for x
   x = 143,079,486.95/13,172.27
6. Step 6: Final answer
   x = 10,862.18