Finding the Third Proportional to 31,779 and 69,781.50

Step by Step Solution

1. Step 1: Write the proportion equation
   31,779 : 69,781.50 = 69,781.50 : x
2. Step 2: Convert to fraction form
   31,779/69,781.50 = 69,781.50/x
3. Step 3: Cross multiply
   31,779x = 69,781.50 × 69,781.50
4. Step 4: Simplify right side
   31,779x = 4,869,457,742.25
5. Step 5: Solve for x
   x = 4,869,457,742.25/31,779
6. Step 6: Final answer
   x = 153,228.79