Finding the Third Proportional to 853.31 and 1,287.56

Step by Step Solution

1. Step 1: Write the proportion equation
   853.31 : 1,287.56 = 1,287.56 : x
2. Step 2: Convert to fraction form
   853.31/1,287.56 = 1,287.56/x
3. Step 3: Cross multiply
   853.31x = 1,287.56 × 1,287.56
4. Step 4: Simplify right side
   853.31x = 1,657,817.19
5. Step 5: Solve for x
   x = 1,657,817.19/853.31
6. Step 6: Final answer
   x = 1,942.80