Finding the Fourth Proportional to 1,920.05, 2,648.46 and 1,211.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,920.05 : 2,648.46 = 1,211.30 : x
2. Step 2: Convert to fraction form
   1,920.05/2,648.46 = 1,211.30/x
3. Step 3: Cross multiply
   1,920.05x = 2,648.46 × 1,211.30
4. Step 4: Simplify right side
   1,920.05x = 3,208,079.60
5. Step 5: Solve for x
   x = 3,208,079.60/1,920.05
6. Step 6: Final answer
   x = 1,670.83