Finding the Fourth Proportional to 2,665.68, 3,979.35 and 2,117.10

Step by Step Solution

1. Step 1: Write the proportion equation
   2,665.68 : 3,979.35 = 2,117.10 : x
2. Step 2: Convert to fraction form
   2,665.68/3,979.35 = 2,117.10/x
3. Step 3: Cross multiply
   2,665.68x = 3,979.35 × 2,117.10
4. Step 4: Simplify right side
   2,665.68x = 8,424,681.89
5. Step 5: Solve for x
   x = 8,424,681.89/2,665.68
6. Step 6: Final answer
   x = 3,160.43