Question 1

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

Accepted Answer

Grades of A, B, or C represent an ordinal level of measurement because they indicate a rank order (A is higher than B, which is higher than C) without specifying the exact differences in performance between these grades.

Question 2

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 it involves collecting data on a phenomenon (in this case, political preference) without attempting to influence the outcome or conditions. The pollster is merely observing and reporting the current state of public opinion.

Question 3

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

Accepted Answer

The classification from softest to hardest implies a ranking order, which corresponds to the ordinal level of measurement. This level allows for the ordering of items based on some attribute or characteristic.

Question 4

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

Accepted Answer

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

Question 5

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 6

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

Accepted Answer

Level of satisfaction is best measured on an ordinal scale because responses can be ranked in order (e.g., very satisfied, satisfied, neutral, dissatisfied, very dissatisfied), but the intervals between these ranks are not necessarily equal.

Question 7

Identify which type of sampling is used. numbers, then interviews the voters corresponding to those numbers.

Accepted Answer

The description suggests that voters are selected using random numbers, which corresponds to random sampling.

Question 8

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 that is expected to affect the outcome, allowing for more precise comparisons within each block.

Question 9

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

Accepted Answer

Systematic sampling is used when every nth element in the population is selected for the sample, as in this case where every 150,000th name was surveyed.

Question 10

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 11

The good design of experiments includes blinding, _____________, and __________________.

Accepted Answer

Good experimental design includes blinding, replication, and randomization to ensure the reliability and validity of the results. Replication allows for the experiment's results to be verified by repeating the experiment, and randomization helps to eliminate bias by randomly assigning subjects to different groups.

Question 12

In a cross-sectional study, data are _____________

Accepted Answer

Cross-sectional studies involve observing, measuring, and collecting data at a single point in time to analyze a population or a specific subset within the population.

Question 13

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

Accepted Answer

The research team is using stratified sampling because they are dividing the population into smaller groups (strata) based on majors and then sampling from these groups in proportions that reflect their actual distribution in the U.S. college student population. This ensures that each major is represented in the sample in proportion to its actual prevalence among all U.S. college students.

Question 14

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

Accepted Answer

Salaries of college professors are measured on a ratio scale because they have a true zero point (meaning no salary or absence of money) and the differences between values are meaningful.

Question 15

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 is observing and recording information without attempting to influence or modify the participants' behavior.

Question 16

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

This is an experiment because the doctor actively intervenes by giving a new medication to one group and a placebo to another, then observes the outcomes.

Question 17

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

Accepted Answer

This is a cross-sectional study because it examines a population at a single point in time to collect data on its current status, in this case, employment data.

Question 18

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 because the tax auditor is selecting every 1000th income tax return, which involves a fixed interval for selection.

Question 19

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

Accepted Answer

The ratio level of measurement includes characteristics such as having a natural zero starting point, the ability to be arranged in order, and meaningful differences between data values. The statement that it "Cannot be arranged in order" does not apply to the ratio level of measurement, as one of its defining features is the ability to order data values.

Question 20

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

Accepted Answer

Ignoring missing data can lead to biased estimates and weaken the generalizability of the study findings. Other methods like deletion, substitution, or assessing the randomness of missing values are considered more appropriate strategies for handling missing data.

Quiz 1: Introduction to Statistics