Finding the Fourth Proportional to 2,840.56, 3,916.72 and 2,279.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,840.56 : 3,916.72 = 2,279.20 : x
2. Step 2: Convert to fraction form
   2,840.56/3,916.72 = 2,279.20/x
3. Step 3: Cross multiply
   2,840.56x = 3,916.72 × 2,279.20
4. Step 4: Simplify right side
   2,840.56x = 8,926,988.22
5. Step 5: Solve for x
   x = 8,926,988.22/2,840.56
6. Step 6: Final answer
   x = 3,142.69