PUBH.3010 Introduction to Biostatistics, Quiz 4 6. Public health professionals want to compare the mean particulate matter (PM2.5) levels between two (2) cities. Which of the following tests of significance should they conduct? Chi square test Independent (2-sample) t-test One sample t-test 7. Researchers collected body mass index (BMI) data for 100 people. The mean BMI was 28.5 and the standard deviation was 2. The researchers want to conduct a one sample t-test to Alpha = 0.05. determine if the sample was likely to have been drawn from a population with a mean BMI=25. 7a) Write the null and alternative hypotheses for this test of significance. (1 point) Soulev-g a ed forinso enedmun offwallet erit to rain 7b) Calculate the number of degrees of freedom. (1 point) ce.0 0 7c) Find the critical value. (1 point) 7d) The calculated t-statistic is 17.5. What should the researchers do? The researchers should reject the null hypothesis The researchers should fail to reject the null hypothesis toelloa elsholes 8. Researchers collected data about number of minutes of physical activity per day for a sample of 50 high school students and 50 university students. The mean for the high school students was 75 minutes (standard deviation = 5 minutes). The mean for the university students was 60 (standard deviation = 10 minutes). Alpha = 0.05. They want to compare the mean number of minutes of physical activity per day for the two groups. 8a) Write the null and alternative hypotheses for this test of significance. (1 point) diviton Inalayrig to level bro erlome jude stab helbollog al sniffal sehopeleo 8b) Calculate the degrees of freedom. (1 point) 8c) The (calculated) t-statistic is 9.5. Use the t-statistic table to estimate the p-value (1 point). NPUBH.3010 Introduction to Biostatistics, Quiz 4 Name: Select one answer unless otherwise stated for multiple choice questions. You must show your work for all calculations to receive full credit. Assume that alpha = 0.05 and that all tests of correct answer. significance are two-sided. All multiple choice questions are worth 1 point and only have 1 1. A study of 100 firefighters compared the occurrence of injuries between volunteers and paid firefighters using a chi square test. The researchers decided to use alpha = 0.10 and calculate 90% confidence intervals. The p-value for this test of significance was 0.06. Which of the following is correct? The researchers should accept the null hypothesis The researchers should reject the null hypothesis The researchers should fail to reject the null hypothesis 2. Which of the following numbers cannot be a p-value? 1.5 0.90 0.5 0.001 (nlog ?) oulaw Isoufto on ari (at 3. If we fail to reject the null hypothesis, then the result is statistically significant. True False 4. Public health professionals collected data about number of cigarettes smoked per day in two (2) neighborhoods. They want to compare the mean number of cigarettes smoked by people in the two (2) neighborhoods. Which of the following tests of significance should they conduct? Chi square test nebhele) esh Independent (2-sample) t-test lavriq to eatunim to redmount ne One sample t-test igle to le 5. Public health professionals collected data about smoking and level of physical activity for 1,000 people. There were 3 categories for the smoking variable (never, former, and current) and 2 categories for physical activity (active and sedentary). Which of the following tests of significance should they conduct to investigate the relationship between these two variables? Chi square test Independent (2-sample) t-test oldest oil One sample t-testPUBH.3010 Introduction to Biostatistics, Quiz 4 9. Public health professionals collected data and created the following contingency table. They want to conduct a chi square test. Have anxiety Yes No Total Food security Low 50 50 100 Moderate 80 120 200 High 40 60 100 High 170 230 400 9a) Write the null and alternative hypotheses for this test of significance. (1 point) 9b) Calculate the degrees of freedom. (1 point) 9c) Find the critical value. (1 point) 9d) The calculated chi square value is 3.07. What should the researchers do? The researchers should reject the null hypothesis The researchers should fail to reject the null hypothesis ge) What is the p-value for this test of significance? Op0.05 One sample best arid level no ventote tro Which of the