In June 2008, the Journal of the American Academy of Dermatology reported on the use of an intermittent therapy for flare prevention and long-term disease control of eczema (red, inflamed, itchy skin). Eczema is a chronic skin disease that affects about 10% to 20% of infants and about 3% of adults and children in the United States. Researchers wanted to determine whether intermittent dosing with a specific topical inhibitor is effective in preventing eczema flare-ups in patients with stabilized eczema. Initially, 383 adults and children with moderate to severe eczema were treated with daily doses of the topical inhibitor. After 16 weeks, 197 were disease free and admitted into the maintenance phase of the study. These patients were randomized to a 3-times-weekly treatment with either the topical inhibitor or a placebo for 40 weeks. All tubes of ointments (topical inhibitor and placebo) were packaged in identical boxes and labeled "for investigational use only." Then the packages were sealed with tamper-proof seals and shipped. Neither the researchers nor the patients knew who received the topical inhibitor or who received the placebo. During the maintenance phase researchers tracked the number of flare-free days for each patient.

Which of the following design features contributes to double blinding?

	a.	Randomization of patients to one of two groups
	b.	Disguising the packaging for both treatments
	c.	The number of flare-free days for each patient

2. Serial KillerThe Murder Accountability Project has compiled a database of homicides in the United States from 1976-2017. This data set includes

• record: ID of the incident given as an integer number
• age of victim: in years
• age of perpetrator: in years
• sex: 1 = female, 0 = male
• ethnicity of victim(s)
• ethnicity of perpetrator
• weapon used

Which of the following variables is quantitative?

a	record
b	sex
c	age of victim

3. Consumer Reports analyzed a dataset of 77 breakfast cereals. Here is a part of the dataset.

(Note: Consumer Reports is an non-profit organization that rates products in an effort to help consumers make informed decisions.)

Indicate whether the following variable is categorical or quantitative:

Target

	a.	Quantitative
	b.	Neither
	c.	Categorical