Finding the Third Proportional to 991.31 and 1,663.69

Step by Step Solution

1. Step 1: Write the proportion equation
   991.31 : 1,663.69 = 1,663.69 : x
2. Step 2: Convert to fraction form
   991.31/1,663.69 = 1,663.69/x
3. Step 3: Cross multiply
   991.31x = 1,663.69 × 1,663.69
4. Step 4: Simplify right side
   991.31x = 2,767,856.10
5. Step 5: Solve for x
   x = 2,767,856.10/991.31
6. Step 6: Final answer
   x = 2,792.11