Finding the Fourth Proportional to 7,128.44, 10,688.72 and 2,196.70

Step by Step Solution

1. Step 1: Write the proportion equation
   7,128.44 : 10,688.72 = 2,196.70 : x
2. Step 2: Convert to fraction form
   7,128.44/10,688.72 = 2,196.70/x
3. Step 3: Cross multiply
   7,128.44x = 10,688.72 × 2,196.70
4. Step 4: Simplify right side
   7,128.44x = 23,479,911.22
5. Step 5: Solve for x
   x = 23,479,911.22/7,128.44
6. Step 6: Final answer
   x = 3,293.84