A professor states that in the United States the proportion of college students who own iPhones is .66. She then splits the class into two groups: Group 1 with students whose last name begins with A-K and Group 2 with students whose last name begins with L-Z. She then asks each group to count how many in that group own iPhones and to calculate the group proportion of iPhone ownership. For Group 1 the proportion is p1 and for Group 2 the proportion is p2. To calculate the proportion you take the number of iPhone owners and divide by the total number of students in the group. You will get a number between 0 and 1.
- What would you expect p1 and p2 to be?
- Do you expect either of these proportions to be vastly different from the population proportion of .66?
- Would you be surprised if p1 was different than p2?
- Would you be surprised if they were the same or similar?
- What statistical concept describes the relationship between the first letter of someone’s last name and whether or not they own an iPhone?