Finding the Fourth Proportional to 12,985.54, 19,513.47 and 7,066.80

Step by Step Solution

1. Step 1: Write the proportion equation
   12,985.54 : 19,513.47 = 7,066.80 : x
2. Step 2: Convert to fraction form
   12,985.54/19,513.47 = 7,066.80/x
3. Step 3: Cross multiply
   12,985.54x = 19,513.47 × 7,066.80
4. Step 4: Simplify right side
   12,985.54x = 137,897,789.80
5. Step 5: Solve for x
   x = 137,897,789.80/12,985.54
6. Step 6: Final answer
   x = 10,619.33