Finding the Fourth Proportional to 9,321.05, 12,870.83 and 6,191.21

Step by Step Solution

1. Step 1: Write the proportion equation
   9,321.05 : 12,870.83 = 6,191.21 : x
2. Step 2: Convert to fraction form
   9,321.05/12,870.83 = 6,191.21/x
3. Step 3: Cross multiply
   9,321.05x = 12,870.83 × 6,191.21
4. Step 4: Simplify right side
   9,321.05x = 79,686,011.40
5. Step 5: Solve for x
   x = 79,686,011.40/9,321.05
6. Step 6: Final answer
   x = 8,549.04