Finding the Third Proportional to 31,278 and 42,138

Step by Step Solution

1. Step 1: Write the proportion equation
   31,278 : 42,138 = 42,138 : x
2. Step 2: Convert to fraction form
   31,278/42,138 = 42,138/x
3. Step 3: Cross multiply
   31,278x = 42,138 × 42,138
4. Step 4: Simplify right side
   31,278x = 1,775,611,044
5. Step 5: Solve for x
   x = 1,775,611,044/31,278
6. Step 6: Final answer
   x = 56,768.69