Finding the Third Proportional to 866.81 and 1,438.69

Step by Step Solution

1. Step 1: Write the proportion equation
   866.81 : 1,438.69 = 1,438.69 : x
2. Step 2: Convert to fraction form
   866.81/1,438.69 = 1,438.69/x
3. Step 3: Cross multiply
   866.81x = 1,438.69 × 1,438.69
4. Step 4: Simplify right side
   866.81x = 2,069,821.72
5. Step 5: Solve for x
   x = 2,069,821.72/866.81
6. Step 6: Final answer
   x = 2,387.85