Finding the Fourth Proportional to 2,779.56, 4,165.86 and 1,315.80

Step by Step Solution

1. Step 1: Write the proportion equation
   2,779.56 : 4,165.86 = 1,315.80 : x
2. Step 2: Convert to fraction form
   2,779.56/4,165.86 = 1,315.80/x
3. Step 3: Cross multiply
   2,779.56x = 4,165.86 × 1,315.80
4. Step 4: Simplify right side
   2,779.56x = 5,481,438.59
5. Step 5: Solve for x
   x = 5,481,438.59/2,779.56
6. Step 6: Final answer
   x = 1,972.05