Finding the Third Proportional to 1,890.56 and 3,978.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,890.56 : 3,978.56 = 3,978.56 : x
2. Step 2: Convert to fraction form
   1,890.56/3,978.56 = 3,978.56/x
3. Step 3: Cross multiply
   1,890.56x = 3,978.56 × 3,978.56
4. Step 4: Simplify right side
   1,890.56x = 15,828,959.57
5. Step 5: Solve for x
   x = 15,828,959.57/1,890.56
6. Step 6: Final answer
   x = 8,372.62