Finding the Fourth Proportional to 2,172.93, 3,258.90 and 613.10

Step by Step Solution

1. Step 1: Write the proportion equation
   2,172.93 : 3,258.90 = 613.10 : x
2. Step 2: Convert to fraction form
   2,172.93/3,258.90 = 613.10/x
3. Step 3: Cross multiply
   2,172.93x = 3,258.90 × 613.10
4. Step 4: Simplify right side
   2,172.93x = 1,998,015.30
5. Step 5: Solve for x
   x = 1,998,015.30/2,172.93
6. Step 6: Final answer
   x = 919.50