Finding the Fourth Proportional to 13,196.40, 19,805.40 and 12,764.40

Step by Step Solution

1. Step 1: Write the proportion equation
   13,196.40 : 19,805.40 = 12,764.40 : x
2. Step 2: Convert to fraction form
   13,196.40/19,805.40 = 12,764.40/x
3. Step 3: Cross multiply
   13,196.40x = 19,805.40 × 12,764.40
4. Step 4: Simplify right side
   13,196.40x = 252,804,047.76
5. Step 5: Solve for x
   x = 252,804,047.76/13,196.40
6. Step 6: Final answer
   x = 19,157.05