Finding the Fourth Proportional to 2,820.42, 3,887.39 and 2,155.82

Step by Step Solution

1. Step 1: Write the proportion equation
   2,820.42 : 3,887.39 = 2,155.82 : x
2. Step 2: Convert to fraction form
   2,820.42/3,887.39 = 2,155.82/x
3. Step 3: Cross multiply
   2,820.42x = 3,887.39 × 2,155.82
4. Step 4: Simplify right side
   2,820.42x = 8,380,499.06
5. Step 5: Solve for x
   x = 8,380,499.06/2,820.42
6. Step 6: Final answer
   x = 2,971.37