Finding the Fourth Proportional to 1,855.78, 2,779.72 and 1,392.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,855.78 : 2,779.72 = 1,392.86 : x
2. Step 2: Convert to fraction form
   1,855.78/2,779.72 = 1,392.86/x
3. Step 3: Cross multiply
   1,855.78x = 2,779.72 × 1,392.86
4. Step 4: Simplify right side
   1,855.78x = 3,871,764.27
5. Step 5: Solve for x
   x = 3,871,764.27/1,855.78
6. Step 6: Final answer
   x = 2,086.33