Finding the Fourth Proportional to 2,156.86, 2,969.64 and 1,959.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,156.86 : 2,969.64 = 1,959.78 : x
2. Step 2: Convert to fraction form
   2,156.86/2,969.64 = 1,959.78/x
3. Step 3: Cross multiply
   2,156.86x = 2,969.64 × 1,959.78
4. Step 4: Simplify right side
   2,156.86x = 5,819,841.08
5. Step 5: Solve for x
   x = 5,819,841.08/2,156.86
6. Step 6: Final answer
   x = 2,698.29