Finding the Third Proportional to 1,421.75 and 1,990.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,421.75 : 1,990.88 = 1,990.88 : x
2. Step 2: Convert to fraction form
   1,421.75/1,990.88 = 1,990.88/x
3. Step 3: Cross multiply
   1,421.75x = 1,990.88 × 1,990.88
4. Step 4: Simplify right side
   1,421.75x = 3,963,583.27
5. Step 5: Solve for x
   x = 3,963,583.27/1,421.75
6. Step 6: Final answer
   x = 2,787.82