Finding the Fourth Proportional to 2,820.34, 3,918.91 and 2,789.92

Step by Step Solution

1. Step 1: Write the proportion equation
   2,820.34 : 3,918.91 = 2,789.92 : x
2. Step 2: Convert to fraction form
   2,820.34/3,918.91 = 2,789.92/x
3. Step 3: Cross multiply
   2,820.34x = 3,918.91 × 2,789.92
4. Step 4: Simplify right side
   2,820.34x = 10,933,445.39
5. Step 5: Solve for x
   x = 10,933,445.39/2,820.34
6. Step 6: Final answer
   x = 3,876.64