Finding the Fourth Proportional to 9,381.78, 12,946.33 and 5,131.99

Step by Step Solution

1. Step 1: Write the proportion equation
   9,381.78 : 12,946.33 = 5,131.99 : x
2. Step 2: Convert to fraction form
   9,381.78/12,946.33 = 5,131.99/x
3. Step 3: Cross multiply
   9,381.78x = 12,946.33 × 5,131.99
4. Step 4: Simplify right side
   9,381.78x = 66,440,436.10
5. Step 5: Solve for x
   x = 66,440,436.10/9,381.78
6. Step 6: Final answer
   x = 7,081.86