Question

(assume the conditions are met, but do all of the other steps for a hypothesis test):

The average life expectancy of a cat is 13 years and cat ages are known to be approximately Normally distributed. A veterinarian claims to have developed a drug that increases feline life span. To test this claim, another vet injects 12 randomly selected cats with this drug at birth. The average life of these cats (in years) that received the drug was recorded.

14.4 9.9 14.0 12.5 15.3 17.5 18.9 14.6 11.1 20.4 16.3 16.1

This sample has a mean of 15.08 years with a standard deviation of 3.05 years. Does this sample of data provide sufficient evidence to believe that this drug is effective at the 2% level of significance?

Answer 1

To Test :-

H0 :-  

H1 :-  

Test Statistic :-


t = 2.3624

Test Criteria :-
Reject null hypothesis if


Result :- Reject null hypothesis

Decision based on P value
P - value = P ( t > 2.3624 ) = 0.0188
Reject null hypothesis if P value <    level of significance
P - value = 0.0188 < 0.02 ,hence we reject null hypothesis
Conclusion :- Reject null hypothesis

There is sufficient evidence to support the claim that a drug that increases feline life span.