Finding the Fourth Proportional to 3,688.72, 5,090.22 and 2,116.60

Step by Step Solution

1. Step 1: Write the proportion equation
   3,688.72 : 5,090.22 = 2,116.60 : x
2. Step 2: Convert to fraction form
   3,688.72/5,090.22 = 2,116.60/x
3. Step 3: Cross multiply
   3,688.72x = 5,090.22 × 2,116.60
4. Step 4: Simplify right side
   3,688.72x = 10,773,959.65
5. Step 5: Solve for x
   x = 10,773,959.65/3,688.72
6. Step 6: Final answer
   x = 2,920.79