Finding the Fourth Proportional to 12,820.43, 17,690.60 and 7,155.49

Step by Step Solution

1. Step 1: Write the proportion equation
   12,820.43 : 17,690.60 = 7,155.49 : x
2. Step 2: Convert to fraction form
   12,820.43/17,690.60 = 7,155.49/x
3. Step 3: Cross multiply
   12,820.43x = 17,690.60 × 7,155.49
4. Step 4: Simplify right side
   12,820.43x = 126,584,918.23
5. Step 5: Solve for x
   x = 126,584,918.23/12,820.43
6. Step 6: Final answer
   x = 9,873.69