Question

1. A public health official in Tennessee wants to know the difference of COVID-19 mortality rate between the States of Tennessee and New York as of April 8, 2020.

Of 4,362 confirmed cases in Tennessee, 79 deaths reported with a mortality rate of 1.8% or 0.018 (79/4362).

Of 149,401 confirmed cases in New York, 6,268 deaths reported with a mortality rate of 4.2% or 0.042 (6,268 /149,401).

Is the COVID-19 mortality rate of Tennessee significantly less than that of New York? (Please perform one-tailed Z test for the proportion difference)

        

1. State the statistical hypotheses (using both statistical notations and

           English statements)  

TYPE YOUR ANSWERS BELOW:

                  ______

                 

        

         (b)     Choose the significance level  

                  α = .05

        

         (c)     Given the test statistic below, you do not need to compute it

       Z_obs = - 8.00

        

      

         (d)     Determine the critical region in this study

Answer 1

(a) The Hypothesis:

H0: p₁ = p₂ : The mortality rate of Tennessee is equal to the mortality rate of New York.

Ha: p₁ < p₂ : The mortality rate of Tennessee is lesser than the mortality rate of New York.

(b) = 0.05

(c) Z = -8.00

(d) The critical region (left tailed) = -1.645

_________________________________

The p value = 0.0000

The Decision: Since Z observed is < -1.645, Reject H0.

The Conclusion: There is sufficient evidence at the 95% significance level to conclude that the mortality rate of Tennessee is lesser than the mortality rate of New York.