Stats 2.0

A researcher records the number of classes each student is enrolled in during the semester. Because the values must be whole-number counts rather than measurements that can take any value within an interval, what type of data is being collected?

Quantitative discrete

A researcher measures the weight of each student's backpack using a scale. Because backpack weight can take decimal values and can vary along a continuous range, what type of data is being collected?

Quantitative continuous

A university survey records the ZIP code associated with each student's home address. Although ZIP codes contain numbers, the numbers function as labels rather than measurements. What type of data is this?

Qualitative categorical

A researcher asks students to identify their primary method of transportation to campus, with responses such as car, bus, walking, or bicycle. What type of data is being collected?

Qualitative categorical

A researcher measures the amount of time each student spends talking on the phone each day. A student's time could be recorded as 35 minutes, 35.5 minutes, or 35.75 minutes. What type of data is this?

Quantitative continuous

A researcher asks each student how many siblings they have. Since the number of siblings is a count that cannot normally be expressed as a fraction, what type of data is being collected?

Quantitative discrete

A researcher wants to show the proportion of students whose favorite transportation method is car, bus, walking, or bicycle. Which graph would most appropriately display how the categories make up the whole group?

Pie chart

A researcher has quantitative measurements and wants to organize them into intervals such as 10 to less than 13, 13 to less than 16, and 16 to less than 19. Which graph is most appropriate for displaying these grouped numerical values?

Histogram

A researcher displays categorical responses using rectangular bars with visible spaces between the bars. Which type of graph has been created?

Bar graph

A researcher groups quantitative measurements into numerical intervals and displays the frequencies with adjacent bars that touch one another. Which type of graph is being used?

Histogram

GSU researchers want a sample that includes students from Math, English, Science, History, and Fine Arts. They divide the population into these departments and randomly select 10 students from each department. Which sampling method is being used?

Stratified sampling

GSU researchers randomly select two entire departments and then include every student within those selected departments in the study. Which sampling method does this describe?

Cluster sampling

A researcher randomly chooses the 7th person leaving a stadium and then surveys every 25th person who leaves afterward. Which sampling method is being used?

Systematic sampling

A researcher has a complete list of students and randomly selects individual students so that every student has an equal chance of being chosen. Which sampling method is being used?

Simple random sampling

A researcher needs participants quickly and surveys people who are easiest to reach because they are already inside a nearby store. Which sampling method is being used?

Convenience sampling

A college wants to estimate how much students study each week, but researchers survey only students who happen to be studying inside the library at 8 PM. Why might the resulting sample be problematic?

The biggest concern is sampling bias.

A survey about a controversial issue allows people to participate only if they choose to volunteer. People with extremely strong opinions are more likely to respond than people with moderate or no opinions. What sampling problem could result?

Self-selected or volunteer sample

A survey asks, "Don't you agree that the university should finally make this obvious improvement?" rather than presenting the issue neutrally. What problem could this wording create?

Undue influence or leading wording

Ice cream sales increase during the same months that drowning deaths increase. A researcher concludes that eating ice cream causes people to drown. Which concept explains why this conclusion may be incorrect?

Confounding

A university divides its student population into departments and randomly selects a proportionate number of students from every department. What is the primary purpose of using this approach?

To make sure every group is represented.