Finding the Third Proportional to 788.91 and 1,221.33

Step by Step Solution

1. Step 1: Write the proportion equation
   788.91 : 1,221.33 = 1,221.33 : x
2. Step 2: Convert to fraction form
   788.91/1,221.33 = 1,221.33/x
3. Step 3: Cross multiply
   788.91x = 1,221.33 × 1,221.33
4. Step 4: Simplify right side
   788.91x = 1,491,642.39
5. Step 5: Solve for x
   x = 1,491,642.39/788.91
6. Step 6: Final answer
   x = 1,890.77