Finding the Fourth Proportional to 3,870.21, 5,806.15 and 1,273.05

Step by Step Solution

1. Step 1: Write the proportion equation
   3,870.21 : 5,806.15 = 1,273.05 : x
2. Step 2: Convert to fraction form
   3,870.21/5,806.15 = 1,273.05/x
3. Step 3: Cross multiply
   3,870.21x = 5,806.15 × 1,273.05
4. Step 4: Simplify right side
   3,870.21x = 7,391,487.04
5. Step 5: Solve for x
   x = 7,391,487.04/3,870.21
6. Step 6: Final answer
   x = 1,909.84