Finding the Fourth Proportional to 12,189.81, 18,287.46 and 3,870.10

Step by Step Solution

1. Step 1: Write the proportion equation
   12,189.81 : 18,287.46 = 3,870.10 : x
2. Step 2: Convert to fraction form
   12,189.81/18,287.46 = 3,870.10/x
3. Step 3: Cross multiply
   12,189.81x = 18,287.46 × 3,870.10
4. Step 4: Simplify right side
   12,189.81x = 70,774,321.81
5. Step 5: Solve for x
   x = 70,774,321.81/12,189.81
6. Step 6: Final answer
   x = 5,806.02