Finding the Third Proportional to 2,190 and 3,128.25

Step by Step Solution

1. Step 1: Write the proportion equation
   2,190 : 3,128.25 = 3,128.25 : x
2. Step 2: Convert to fraction form
   2,190/3,128.25 = 3,128.25/x
3. Step 3: Cross multiply
   2,190x = 3,128.25 × 3,128.25
4. Step 4: Simplify right side
   2,190x = 9,785,948.06
5. Step 5: Solve for x
   x = 9,785,948.06/2,190
6. Step 6: Final answer
   x = 4,468.47