Finding the Fourth Proportional to 9,142.18, 12,606.78 and 7,820.26

Step by Step Solution

1. Step 1: Write the proportion equation
   9,142.18 : 12,606.78 = 7,820.26 : x
2. Step 2: Convert to fraction form
   9,142.18/12,606.78 = 7,820.26/x
3. Step 3: Cross multiply
   9,142.18x = 12,606.78 × 7,820.26
4. Step 4: Simplify right side
   9,142.18x = 98,588,297.36
5. Step 5: Solve for x
   x = 98,588,297.36/9,142.18
6. Step 6: Final answer
   x = 10,783.89