1. Assume a prevalence of 80% during the flu season in Baltimore. Assume 50% sensitivity and 80% specificity for the rapid influenza test. What is the positive predictive value of the rapid influenza test in Baltimore during flu season?

a. 93%

b. 91%

c. 95%

d. 98%

2. Using the table below which includes data from the CDC website, for Thursday, June 23, 2022, calculate the total case fatality of COVID-19 in the US as of that date.

Total US COVID Cases	7-day COVID Case Rate per 100, 000 in the US	Total US COVID Deaths
86,512,787	205.4	1,010,090

a. 3.4%

b. 2.3%

c. 1.17%

d. 2.02 per 10,000

3. Using table 1 entitled "Diabetes and Obesity Prevalence in the NHIS and BRFSS", calculate the ratio of prevalence of obesity in 2015 to the prevalence of obesity in 2000.

a. 1.40

b. 1.49

c. 1.55

d. 0.58

4. A study was undertaken to examine the efficacy of a new vaccine. A total of 10,000 individuals were randomized to receive the vaccine or placebo. The incidence of influenza-like episodes among those receiving the placebo was 600 cases per 1,000, and in the vaccine group it was 150 cases per 1,000 during the study period. What is the estimated efficacy of this new vaccine?

a. 75%

b. 60%

c. 50%

d. 82%