Finding the Fourth Proportional to 13,316.72, 19,978.20 and 3,956.81

Step by Step Solution

1. Step 1: Write the proportion equation
   13,316.72 : 19,978.20 = 3,956.81 : x
2. Step 2: Convert to fraction form
   13,316.72/19,978.20 = 3,956.81/x
3. Step 3: Cross multiply
   13,316.72x = 19,978.20 × 3,956.81
4. Step 4: Simplify right side
   13,316.72x = 79,049,841.65
5. Step 5: Solve for x
   x = 79,049,841.65/13,316.72
6. Step 6: Final answer
   x = 5,936.14