Finding the Fourth Proportional to 3,970.28, 5,477.86 and 3,128.37

Step by Step Solution

1. Step 1: Write the proportion equation
   3,970.28 : 5,477.86 = 3,128.37 : x
2. Step 2: Convert to fraction form
   3,970.28/5,477.86 = 3,128.37/x
3. Step 3: Cross multiply
   3,970.28x = 5,477.86 × 3,128.37
4. Step 4: Simplify right side
   3,970.28x = 17,136,787.07
5. Step 5: Solve for x
   x = 17,136,787.07/3,970.28
6. Step 6: Final answer
   x = 4,316.26