Finding the Fourth Proportional to 12,987.13, 17,922.24 and 7,399.21

Step by Step Solution

1. Step 1: Write the proportion equation
   12,987.13 : 17,922.24 = 7,399.21 : x
2. Step 2: Convert to fraction form
   12,987.13/17,922.24 = 7,399.21/x
3. Step 3: Cross multiply
   12,987.13x = 17,922.24 × 7,399.21
4. Step 4: Simplify right side
   12,987.13x = 132,610,417.43
5. Step 5: Solve for x
   x = 132,610,417.43/12,987.13
6. Step 6: Final answer
   x = 10,210.91