Finding the Fourth Proportional to 12,810.30, 17,678.35 and 7,145.01

Step by Step Solution

1. Step 1: Write the proportion equation
   12,810.30 : 17,678.35 = 7,145.01 : x
2. Step 2: Convert to fraction form
   12,810.30/17,678.35 = 7,145.01/x
3. Step 3: Cross multiply
   12,810.30x = 17,678.35 × 7,145.01
4. Step 4: Simplify right side
   12,810.30x = 126,311,996.46
5. Step 5: Solve for x
   x = 126,311,996.46/12,810.30
6. Step 6: Final answer
   x = 9,860.19