Answer: A) Tobt = 2.75 B) Tobt = -2.75
Step-by-step explanation:
- We reject the null hypothesis when the absolute critical t-value is lower than the absolute t-obtained value.
The given t-critical value 

So , we reject null hypothesis , when 

Since, 
 but
 but 

So, the correct options are A) Tobt = 2.75 B) Tobt = -2.75