Finding the Fourth Proportional to 12,390.21, 17,090.72 and 7,350.87

Step by Step Solution

1. Step 1: Write the proportion equation
   12,390.21 : 17,090.72 = 7,350.87 : x
2. Step 2: Convert to fraction form
   12,390.21/17,090.72 = 7,350.87/x
3. Step 3: Cross multiply
   12,390.21x = 17,090.72 × 7,350.87
4. Step 4: Simplify right side
   12,390.21x = 125,631,538.72
5. Step 5: Solve for x
   x = 125,631,538.72/12,390.21
6. Step 6: Final answer
   x = 10,139.58