Stats: 1.1 HW

'Number of times per week' is what type of data? a. qualitative b. quantitative - discrete c. quantitative - continuous

B

A teacher wants to know if her students are doing homework so she randomly selects rows 2 and 5, and then calls on all students in row 2 and all students in row 5 to present the solutions to homework problems to the class. Convenience, stratified, cluster or simple random?

Cluster

In the following situation, indicate whether the potential bias is a selection bias, a nonresponse bias, or a response bias. A telephone survey of 480 residences is conducted. People refused to talk to the interviewer in 100 of the residences.

Nonresponse

The article "Gene's Role in Cancer May Be Overstated" states that "early studies that evaluated breast cancer risk among gene mutation carriers selected women in families where sisters, mothers, and grandmothers all had breast cancer. This created a statistical bias that skewed risk estimates for women in the general population." Is the bias described here selection bias, measurement bias, or nonresponse bias?

Selection Bias

A political party wants to know the reaction of voters to a debate between the candidates. The day after the debate, the party's polling staff calls 1200 randomly selected phone numbers. If a registered voter answers the phone or is available to come to the phone, that registered voter is asked who he/she intends to vote for and whether the debate changed his/her opinion of the candidates. Convenience, stratified, cluster or simple random

Simple random

A study was done to determine the age, number of times per week, and the duration (amount of time) of resident use of a local park in San Jose. The first house in the neighborhood around the park was selected randomly and then every 8th house in the neighborhood around the park was interviewed. What sampling method was used? Convenience, stratified, systematic or simple random?

Systematic

Identify the following quantitative variables as discrete or continuous. (a) Population in a particular area of the United States (b) Weight of newspapers recovered for recycling on a single day (c) Time to complete a sociology exam (d) Number of consumers in a poll of 1000 who consider nutritional labeling on food products to be important

a. Discrete b. Continuous c. Continuous d. Discrete

The student senate at a university with 18,000 students is interested in the proportion of students who favor a change in the grading system to allow for plus and minus grades (e.g., B+, B, B−, rather than just B). Two hundred students are interviewed to determine their attitude toward this proposed change. (a) What is the population of interest? (b) What group of students constitutes the sample in this problem? the entire student body (the 18,000 students), the 200 students interviewed, the 2,000 students interviewed, or all students who favor a change in the grading system the student senate

a. The whole student body b. The 200 students involved

Identify each variable as quantitative or qualitative. (a) Ethnic origin of a candidate for public office (b) Score (0-100) on a placement examination (c) Fast-food establishment preferred by a student (McDonald's, Burger King, or Carl's Jr.) (d) Mercury concentration in a sample of tuna

a. qualitative b. quantitative c. qualitative d. quantitative

A Lake Tahoe Community College instructor is interested in the average number of days Lake Tahoe Community College math students are absent from class during a quarter. The instructor takes her sample by gathering data on 5 randomly selected students from each Lake Tahoe Community College math class. Which type of sampling did she use? Convenience, stratified, cluster or simple random?

stratified sampling