Finding the Third Proportional to 870.50 and 1,781

Step by Step Solution

1. Step 1: Write the proportion equation
   870.50 : 1,781 = 1,781 : x
2. Step 2: Convert to fraction form
   870.50/1,781 = 1,781/x
3. Step 3: Cross multiply
   870.50x = 1,781 × 1,781
4. Step 4: Simplify right side
   870.50x = 3,171,961
5. Step 5: Solve for x
   x = 3,171,961/870.50
6. Step 6: Final answer
   x = 3,643.84