Finding the Fourth Proportional to 9,915.74, 13,683.46 and 5,378.16

Step by Step Solution

1. Step 1: Write the proportion equation
   9,915.74 : 13,683.46 = 5,378.16 : x
2. Step 2: Convert to fraction form
   9,915.74/13,683.46 = 5,378.16/x
3. Step 3: Cross multiply
   9,915.74x = 13,683.46 × 5,378.16
4. Step 4: Simplify right side
   9,915.74x = 73,591,837.23
5. Step 5: Solve for x
   x = 73,591,837.23/9,915.74
6. Step 6: Final answer
   x = 7,421.72