The doctors and u=instructor claims that practicing yoga reduces blood pressure and hence is beneficial to people.
Population mean, μ = 140 mm
Sample mean, = 139 mm
Sample size, n = 51
Sample standard deviation, s = 5 mm
Thus, we can design the null hypothesis and alternate hypothesis as
The null hypothesis states that the population have a blood pressure of 140 mm. The alternate hypothesis states that yoga reduces the blood pressure and the sample has a blood pressure less than 140 mm.