Finding the Third Proportional to 699.50 and 1,428

Step by Step Solution

1. Step 1: Write the proportion equation
   699.50 : 1,428 = 1,428 : x
2. Step 2: Convert to fraction form
   699.50/1,428 = 1,428/x
3. Step 3: Cross multiply
   699.50x = 1,428 × 1,428
4. Step 4: Simplify right side
   699.50x = 2,039,184
5. Step 5: Solve for x
   x = 2,039,184/699.50
6. Step 6: Final answer
   x = 2,915.20