Finding the Fourth Proportional to 2,779.98, 4,170.50 and 931.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,779.98 : 4,170.50 = 931.31 : x
2. Step 2: Convert to fraction form
   2,779.98/4,170.50 = 931.31/x
3. Step 3: Cross multiply
   2,779.98x = 4,170.50 × 931.31
4. Step 4: Simplify right side
   2,779.98x = 3,884,028.36
5. Step 5: Solve for x
   x = 3,884,028.36/2,779.98
6. Step 6: Final answer
   x = 1,397.14