Finding the Fourth Proportional to 5,380.67, 8,058.71 and 5,290.47

Step by Step Solution

1. Step 1: Write the proportion equation
   5,380.67 : 8,058.71 = 5,290.47 : x
2. Step 2: Convert to fraction form
   5,380.67/8,058.71 = 5,290.47/x
3. Step 3: Cross multiply
   5,380.67x = 8,058.71 × 5,290.47
4. Step 4: Simplify right side
   5,380.67x = 42,634,376.72
5. Step 5: Solve for x
   x = 42,634,376.72/5,380.67
6. Step 6: Final answer
   x = 7,923.61