Finding the Fourth Proportional to 9,315.26, 12,860.53 and 5,780.42

Step by Step Solution

1. Step 1: Write the proportion equation
   9,315.26 : 12,860.53 = 5,780.42 : x
2. Step 2: Convert to fraction form
   9,315.26/12,860.53 = 5,780.42/x
3. Step 3: Cross multiply
   9,315.26x = 12,860.53 × 5,780.42
4. Step 4: Simplify right side
   9,315.26x = 74,339,186.07
5. Step 5: Solve for x
   x = 74,339,186.07/9,315.26
6. Step 6: Final answer
   x = 7,980.37