Give null and alternative hypothesizes. 

1. The average age of first-year medical school students is at least 27 years.
2. The average car lifespan in 13.2 years.
   
3. The average experience (in seasons) for an NBA player is 4.71.
4. The average age of first-time home-buyers is 41 years or less.
5. The airspeed velocity of an unladen swallow is less than 30 mph.
6. The average weight gain for professors that talk about bagels in class is 3.2 lbs per semester.