Finding the Fourth Proportional to 5,280.32, 7,286.86 and 2,890.28

Step by Step Solution

1. Step 1: Write the proportion equation
   5,280.32 : 7,286.86 = 2,890.28 : x
2. Step 2: Convert to fraction form
   5,280.32/7,286.86 = 2,890.28/x
3. Step 3: Cross multiply
   5,280.32x = 7,286.86 × 2,890.28
4. Step 4: Simplify right side
   5,280.32x = 21,061,087.55
5. Step 5: Solve for x
   x = 21,061,087.55/5,280.32
6. Step 6: Final answer
   x = 3,988.60