Finding the Fourth Proportional to 1,685.94, 2,516.16 and 1,642.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,685.94 : 2,516.16 = 1,642.20 : x
2. Step 2: Convert to fraction form
   1,685.94/2,516.16 = 1,642.20/x
3. Step 3: Cross multiply
   1,685.94x = 2,516.16 × 1,642.20
4. Step 4: Simplify right side
   1,685.94x = 4,132,037.95
5. Step 5: Solve for x
   x = 4,132,037.95/1,685.94
6. Step 6: Final answer
   x = 2,450.88