Finding the Fourth Proportional to 12,321.90, 17,005.98 and 7,017.21

Step by Step Solution

1. Step 1: Write the proportion equation
   12,321.90 : 17,005.98 = 7,017.21 : x
2. Step 2: Convert to fraction form
   12,321.90/17,005.98 = 7,017.21/x
3. Step 3: Cross multiply
   12,321.90x = 17,005.98 × 7,017.21
4. Step 4: Simplify right side
   12,321.90x = 119,334,559.23
5. Step 5: Solve for x
   x = 119,334,559.23/12,321.90
6. Step 6: Final answer
   x = 9,684.75