Finding the Third Proportional to 53.91 and 61.31

Step by Step Solution

1. Step 1: Write the proportion equation
   53.91 : 61.31 = 61.31 : x
2. Step 2: Convert to fraction form
   53.91/61.31 = 61.31/x
3. Step 3: Cross multiply
   53.91x = 61.31 × 61.31
4. Step 4: Simplify right side
   53.91x = 3,759.22
5. Step 5: Solve for x
   x = 3,759.22/53.91
6. Step 6: Final answer
   x = 69.74