Finding the Fourth Proportional to 2,160.69, 2,980.81 and 1,321.43

Step by Step Solution

1. Step 1: Write the proportion equation
   2,160.69 : 2,980.81 = 1,321.43 : x
2. Step 2: Convert to fraction form
   2,160.69/2,980.81 = 1,321.43/x
3. Step 3: Cross multiply
   2,160.69x = 2,980.81 × 1,321.43
4. Step 4: Simplify right side
   2,160.69x = 3,938,918.51
5. Step 5: Solve for x
   x = 3,938,918.51/2,160.69
6. Step 6: Final answer
   x = 1,822.99