Finding the Third Proportional to 697.78 and 1,405.69

Step by Step Solution

1. Step 1: Write the proportion equation
   697.78 : 1,405.69 = 1,405.69 : x
2. Step 2: Convert to fraction form
   697.78/1,405.69 = 1,405.69/x
3. Step 3: Cross multiply
   697.78x = 1,405.69 × 1,405.69
4. Step 4: Simplify right side
   697.78x = 1,975,957.35
5. Step 5: Solve for x
   x = 1,975,957.35/697.78
6. Step 6: Final answer
   x = 2,831.77