Finding the Fourth Proportional to 2,002.20, 3,004.56 and 1,985.70

Step by Step Solution

1. Step 1: Write the proportion equation
   2,002.20 : 3,004.56 = 1,985.70 : x
2. Step 2: Convert to fraction form
   2,002.20/3,004.56 = 1,985.70/x
3. Step 3: Cross multiply
   2,002.20x = 3,004.56 × 1,985.70
4. Step 4: Simplify right side
   2,002.20x = 5,966,151.12
5. Step 5: Solve for x
   x = 5,966,151.12/2,002.20
6. Step 6: Final answer
   x = 2,979.79