Finding the Fourth Proportional to 12,798, 17,661.42 and 7,830

Step by Step Solution

1. Step 1: Write the proportion equation
   12,798 : 17,661.42 = 7,830 : x
2. Step 2: Convert to fraction form
   12,798/17,661.42 = 7,830/x
3. Step 3: Cross multiply
   12,798x = 17,661.42 × 7,830
4. Step 4: Simplify right side
   12,798x = 138,288,918.60
5. Step 5: Solve for x
   x = 138,288,918.60/12,798
6. Step 6: Final answer
   x = 10,805.51