Using a spreadsheet, statistical software, or an Internet resource, calculate the mean and standard deviation for each group in the data presented below. Then, evaluate the null hypothesis that “Exposure to equivalents of 0, 1, 3, and 5 cigarettes of second-hand smoke does not result in a change in mouse mass” with significance set at p < 0.05.
After completing the descriptive statistics and performing an appropriate hypothesis test, prepare a table to efficiently report the results. Be sure that descriptive statistics and some indication of the hypothesis test’s results are reflected in the table (reject or inability to reject the null hypothesis, with test statistic and p-value utilized). Check that the table meets the guidelines suggested in the textbook, and upload the document to the appropriate link on Blackboard.
Note, the purpose of this exercise is for students to find a solution to the problem utilizing resources that best fit their knowledge, skills and resources. Ideally, students would have access to statistical software, but this is often too expensive or not cost effective for calculating a few values and doing a handful of hypothesis tests. So, use of a spreadsheet with built in functions or a freely available statistical tool on the Internet is perfectly appropriate for this course (other instructors may have different requirements).
The growth of mice was measured with exposure to increasing amounts of second-hand cigarette smoke. Exposure was calibrated to reflect the amount of second-hand smoke produced by the indicated number of cigarettes in a standard 15 square meter room for 1 hour. Fifty mice were randomly divided into 4 groups. Data are the mass, in grams, of mice after 10 weeks of 1 hour per day exposure to the indicated levels of smoke. Control animals were exposed to identical conditions without exposure to smoke.
Control 1 cigarette 3 cigarettes 5 cigarettes 25.1 17.6 17.5 15.5 26.2 25.1 29.2 22.9 23.5 23.8 23.9 17.8 27.3 19.9 25.8 21.6 21.9 27.5 23.2 24.4 19.4 24.2 26.5 22.8 18.7 26.8 22.8 27.6 23.1 24.9 18.9 16.3 24.2 30.2 24.1 14.1 29.5 18.6 16.6 26.4