Question 1

Identify which type of sampling is used. A research team wants to study the demographics of college students in the United States using proportionate samples of students in majors reflecting actual U.S. percentages.

Accepted Answer

The research team is using stratified sampling, as they are dividing the population (college students in the United States) into strata (majors) and selecting proportionate samples from each stratum. This allows them to ensure that their sample reflects the actual percentages within the overall population.

Question 2

A marijuana survey included 1610 responses from a list of approximately 241,500,000 adults in the United States from which every 150,000th name was surveyed. Identify which of these types of sampling is used:

Accepted Answer

The survey is using a systematic sampling method where every 150,000th name from the list is surveyed. This is a type of probability sampling where every member of the population has an equal chance of being selected.

Question 3

The similarity between an ordinal level of measurement and an interval level of measurement is that ________.

Accepted Answer

The answer of The similarity between an ordinal level of...

Question 4

Determine which level of measurement is appropriate. Salaries of college professors.

Accepted Answer

Salaries of college professors are measured at the ratio level, as they have a true zero point (no salary) and they can be compared and analyzed using mathematical operations such as multiplication and division.

Question 5

Which type of experiment separates subjects into groups that are similar but differ in ways that might affect the outcome of the experiment?

Accepted Answer

A randomized block design separates subjects into groups (blocks) that are similar in some way but differ in ways that might affect the outcome, allowing for more accurate comparisons within each block.

Question 6

Identify the type of study used. A town obtains current employment data by polling 10,000 of its citizens this month.

Accepted Answer

The study is cross-sectional because it collects information at a single point in time, rather than tracking changes over time.

Question 7

Identify which type of sampling is used. A pollster uses a computer to generate 500 random numbers, then interviews the voters corresponding to those numbers.

Accepted Answer

The sampling method used is random since the pollster is generating random numbers to choose the voters to interview.

Question 8

A gardener has 75 clients, 45% of whom are businesses. Find the number of business clients.

Accepted Answer

45% of 75 clients is 33.75, which rounds to 34 clients.

Question 9

The good design of experiments includes blinding, ________, and ________.

Accepted Answer

Replication and randomization are key components of a well-designed experiment, ensuring that results are reliable and not due to chance.

Question 10

A marketing firm does a survey to find out how many people use a product. Of the one hundred people contacted, fifteen said they use the product. Identify the type of study used.

Accepted Answer

This is an observational study because the marketing firm simply observed and recorded the responses of the one hundred people, without manipulating any variables or controlling any factors.

Question 11

In a cross-sectional study, data are ________.

Accepted Answer

In a cross-sectional study, data are observed, measured, and collected at one point of time. This contrasts with longitudinal studies, where data are collected over a period of time. Choice A refers to a retrospective study, where data are collected from a past time period. Choice B describes a prospective study, where data are collected in the future from groups that share common factors.

Question 12

Determine whether the given description corresponds to an observational study or an experiment. A political pollster reports that his candidate has a 10% lead in the polls with 10% undecided.

Accepted Answer

This is an observational study because the pollster is simply observing and reporting the results of the polls, rather than manipulating any variables or conducting any interventions.

Question 13

Which of the following is an inappropriate way to deal with missing data?

Accepted Answer

Ignoring missing data can lead to biased results and inaccurate analyses, making it an inappropriate way to handle missing data.

Question 14

Which of the following does not apply to the ratio level of measurement?

Accepted Answer

The ratio level of measurement can be arranged in order and has a natural zero starting point. The differences between data values are meaningful and can be compared. Therefore, the only option that does not apply to the ratio level of measurement is C, as it contradicts the fundamental characteristic of being able to arrange the data in order.

Question 15

Determine whether the given description corresponds to an observational study or an experiment. A doctor gives a new medication to half of his patients with the flu and a placebo to the other half of his patients with the
Flu)

Accepted Answer

In this scenario, the doctor actively intervenes by giving a new medication to one group and a placebo to another, which characterizes it as an experiment.

Question 16

Determine which of the four levels of measurement is most appropriate. Students' grades of A, B, or C, on a test.

Accepted Answer

The grades of A, B, and C can be ranked in a specific order from highest to lowest, but the differences between each grade are not consistent or measurable. Therefore, the most appropriate level of measurement for this data is ordinal.

Question 17

Identify which type of sampling is used. A tax auditor selects every 1000th income tax return that is received.

Accepted Answer

This is an example of systematic sampling as every 1000th income tax return is selected in a structured and consistent manner. It is not random as every return is not given an equal chance of being selected. It is not stratified, convenience or cluster sampling.

Question 18

Determine which of the four levels of measurement is most appropriate. Level of satisfaction of survey respondents.

Accepted Answer

The level of satisfaction of survey respondents is a subjective measure that cannot be quantified or compared to an absolute scale. Therefore, it is most appropriate to use an ordinal level of measurement to rank respondents' satisfaction from lowest to highest.

Question 19

Determine whether the given value is a statistic or a parameter. After taking the first exam, 15 of the students dropped the class.

Accepted Answer

The answer of Determine whether the given value is a...

Question 20

Determine which level of measurement is appropriate. A sample of children's balls are classified from softest to hardest.

Accepted Answer

The given data is classified from softest to hardest, which indicates a natural order or direction. Therefore, the appropriate level of measurement is ordinal.

Quiz 1: Introduction to Statistics