Finding the Fourth Proportional to 3,975.89, 5,511.18 and 3,909.71

Step by Step Solution

1. Step 1: Write the proportion equation
   3,975.89 : 5,511.18 = 3,909.71 : x
2. Step 2: Convert to fraction form
   3,975.89/5,511.18 = 3,909.71/x
3. Step 3: Cross multiply
   3,975.89x = 5,511.18 × 3,909.71
4. Step 4: Simplify right side
   3,975.89x = 21,547,144.00
5. Step 5: Solve for x
   x = 21,547,144.00/3,975.89
6. Step 6: Final answer
   x = 5,419.45