Finding the Fourth Proportional to 2,085.12, 3,124.76 and 1,620.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,085.12 : 3,124.76 = 1,620.78 : x
2. Step 2: Convert to fraction form
   2,085.12/3,124.76 = 1,620.78/x
3. Step 3: Cross multiply
   2,085.12x = 3,124.76 × 1,620.78
4. Step 4: Simplify right side
   2,085.12x = 5,064,548.51
5. Step 5: Solve for x
   x = 5,064,548.51/2,085.12
6. Step 6: Final answer
   x = 2,428.90