Finding the Fourth Proportional to 9,321.77, 12,855.59 and 7,191.99

Step by Step Solution

1. Step 1: Write the proportion equation
   9,321.77 : 12,855.59 = 7,191.99 : x
2. Step 2: Convert to fraction form
   9,321.77/12,855.59 = 7,191.99/x
3. Step 3: Cross multiply
   9,321.77x = 12,855.59 × 7,191.99
4. Step 4: Simplify right side
   9,321.77x = 92,457,238.76
5. Step 5: Solve for x
   x = 92,457,238.76/9,321.77
6. Step 6: Final answer
   x = 9,918.43