Finding the Fourth Proportional to 2,142.79, 3,215.22 and 1,865.67

Step by Step Solution

1. Step 1: Write the proportion equation
   2,142.79 : 3,215.22 = 1,865.67 : x
2. Step 2: Convert to fraction form
   2,142.79/3,215.22 = 1,865.67/x
3. Step 3: Cross multiply
   2,142.79x = 3,215.22 × 1,865.67
4. Step 4: Simplify right side
   2,142.79x = 5,998,539.50
5. Step 5: Solve for x
   x = 5,998,539.50/2,142.79
6. Step 6: Final answer
   x = 2,799.41