Finding the Fourth Proportional to 2,661.35, 3,990.96 and 1,275.30

Step by Step Solution

1. Step 1: Write the proportion equation
   2,661.35 : 3,990.96 = 1,275.30 : x
2. Step 2: Convert to fraction form
   2,661.35/3,990.96 = 1,275.30/x
3. Step 3: Cross multiply
   2,661.35x = 3,990.96 × 1,275.30
4. Step 4: Simplify right side
   2,661.35x = 5,089,671.29
5. Step 5: Solve for x
   x = 5,089,671.29/2,661.35
6. Step 6: Final answer
   x = 1,912.44