Data set: Bacteria Antibacterial agents have become very popular in the marketplace, in products from gels to

Question:

Data set: Bacteria
Antibacterial agents have become very popular in the marketplace, in products from gels to plastic children€™s toys. However, even now, you are surrounded by bacteria. Scientists have known for many years that bacteria are able to adhere to solid surfaces and form a resistant coat; however, it was not until the 1970s that the concept of biofilms became prevalent in the scientific community. These films make completely removing bacteria from a surface nearly impossible.
Why should you care? Before the discovery of vaccines and antibiotics, humans succumbed to a myriad of acute infectious diseases. However, the majority of these have been eradicated or controlled making bacterial infections from biofilms among the most threatening.8 Today, battles against biofilm-forming bacteria are on the front lines of medical research. Interestingly, biofilms coat every surface that you see around you.
Two students, Isaac and Courtney, sampled surfaces around their campus to analyze the prevalence of bacteria. They compared different types of surfaces in both residential and academic buildings.
Data were collected by wiping surfaces with a wet Q-tip and swabbing the result on a standard nutrient agar plate. Locations were all tested on April 24, 2009 over the course of a two- hour period. The plates were incubated at 37° C for 48 hours before colony- forming units ( CFUs) were counted as a measure of bacteria levels. Figure 4.5 shows several of the plates from this study. When CFUs exceeded 400 per plate, one fourth of the plate was counted and the total was calculated from that sample.
Figure 4.5

Pictures of representative plates from Isaac and Courtney€™s samples around campus: (A) a bathroom door handle in Norris, (B) a desk in Noyce (the large cluster is a mold spot, not counted as a CFU), (C) a desk in Yellow House (the white film is a fungus, not counted as a CFU), (D) a desk in ARH, and (E) a bath-room door handle in the Cowles apartment. Photos courtesy of Derek R. Blanchette.
Six different buildings were swabbed, with two buildings representing each type of facility:
€¢ Academic buildings: Noyce and ARH
€¢ Public residential buildings: Norris and Dibble
€¢ Private residences: Cowles apartment 7110 and Yellow House (1478 Park St.)
Within each building, two faucets, two door handles, and two desk surfaces were swabbed.
a. Make the assumption that ANOVA is appropriate for the data (i. e., do not transform any data). Using software, conduct an ANOVA for the data that will analyze all main effects, as well as all two- way interactions. Treat the six buildings as six levels of the Building factor. Treat faucet, desk, and door as three levels of the Location factor.
b. Create appropriate graphs/ charts to check for equal variances and normality. Does it appear that it is appropriate to use ANOVA to analyze these data?
c. Transform the response to the natural log of Count and redo the analysis. How do the results change? Create appropriate graphs to display the main effects and the interaction effects. Describe how the academic buildings ( ARH and Noyce) compare to the other buildings.