Question

Q18. Health Department, NYC plans to release a new drug commercially that is expected to lower

         blood pressure effectively. The drug was administered to a random sample of 20 patients.

         Among these patients the decrease in the blood pressure of 7 patients was recorded and no

         change in blood pressure of other patients was recorded . The decrease in the blood pressure of

         the 7 patients was 21, 22, 16, 19, 20, 23, 19. At 1% level of significance, to support the

         release of drug, Health Department used

         a. mean decrease in blood pressure =20 for test of hypothesis

         b. Critical value t_α/2 = 3.707 was valid value to compare t_STAT

         c. Degree of freedom = 6 were used to get t_α/2 for the conclusion                     

        d none of the above a, b, c are correct for conclusion       

Answer 1

18)

The null and alternate hypothesis are:

H0: i.e. mean decrease is not greater than 0

Ha: i.e. mean decrease is greater than 0

Hence statement (a) is incorrect.

The critical value is:

Hence statement (b) is incorrect.

Also, degrees of freedom is (n-1) = 20-1 = 19

Hence statement (c) is incorrect.

Hence option D is the correct option.