stat chapter 1 quiz notes

Ratio

numbers listed on graph such as annual income or annual rainfall represent which level of measurement?

experimental units

what are the subjects being tested called?

Simple random sampling is​ used, since the business is selecting from its customers at​ random, and all samples of 670 customers have an equal chance of being selected. Biases:The wording of the question asked to the customers may influence them towards a particular response. The results would not be usable in this case.

Chosen at​ random, 670 customers at a bank are contacted and asked their opinions of the service they received. This is an example of which type of sampling? What is a potential source of bias?

Nominal. The data are categorized using numbers, but no mathematical computations can be made.

The jersey numbers for players on a football team are listed below, What is level of measurement for the data set?

Interval

Years listed on the graph are which level of measurement?

qualitative Ordinal

The regions with the six highest volumes of sales for a corporation are shown below. 1. Northern 2. Southeast 3. Western 4. Northwest 5. Eastern 6. Southern. Which type of data is it? What is the data set's level of measurement?

blinded as to whether they are receiving a real treatment or the placebo

A placebo is a fake treatment used in experiments. To minimize the possibility of the subjects reacting favorably to a​ placebo, the subjects will typically be ...?

population: Female University graduates who have a white collar job; a population is the group being studied Sample: The 2520 female university graduates who have a white collar job

A polling organization contacts 2520 female university graduates who have a white collar job and asks whether or not they had received a raise at work during the past 6 months. What is the population? What is the sample?

statistic because the data set of 42 people in a dining hall is a sample.

A survey of 42 out of hundreds in a dining hall showed that 17 enjoyed their meal. What does the underlined value represent (17)?

regular intervals

A systematic sample is a sample in which each member of the population is assigned a number. The members of the population are ordered in some​ way, a starting number is randomly​ selected, and then sample members are selected at what type of intervals from the starting number.

Convenience Sampling because students are chosen due to convenience of location. Biases: Because of the personal nature of the​ question, students may not answer honestly. & The sample only consists of members of the population that are easy to get. These members may not be representative of the population

Assume the population at interest is the student body at a university. Questioning students as they leave an academic building, a researcher asks 367 students about their dating habits. What type of sampling is used? What potential biases are present?

Population: The bottles of vinegar produced in the plant on September 4 Sample: The 60 bottles of vinegar produced in the plant on September 4th

A​ quality-control manager randomly selects 60 bottles of vinegar that were filled on September 4 to assess the calibration of the filling machine. What is the population in this study? Sample?

Data at the nominal level can be put in a category. Data at the interval level can be put in a​ category, put in​ order, and you can find differences between values. ​Therefore, more types of calculations can be performed with data at the interval level than with data at the nominal level.

Can more types of calculations be performed with data at the interval or nominal level?

This is a statistic because the value is a numerical measurement describing a characteristic of a sample.

Determine whether the given value is a statistic or a parameter. A sample of professors is selected and it is found that 55% own a tv.

The variable is qualitative because a favorite sport describes an attribute or characteristic.

Determine whether the variable is quantitative or qualitative. "favorite sport"

members of each group within the population will be sampled

For stratified​ samples, members of the population are divided into two or more​subsets, called strata. A sample is then randomly selected from each of the strata. This ensures that...?

observational study

In a study of 371 women with a particular disease, the subjects were photographed daily. This is an example of ?

What is the population? all the men in the country What is the sample? the 1003 men selected

In a​ poll, 1003 men in a country were asked whether they favor or oppose the use of​ "federal tax dollars to fund medical research using stem cells obtained from human​ embryos." Among the​ respondents, 47​% said that they were in favor. Describe the statistical study. What is the population? what is the sample?

No, because it does not lead the respondent to any particular answer.

Is this question bias? "How often do you go out walking on an average week?"

Yes this is bias Should word it: How do you think eating eggs affects your health?

Is this question bias? If so how would you reword it? Why is eating eggs good for you?

Stratified sampling is​ used, since the field is divided into subplots and a random sample is taken from each subplot. Bias: Certain subplots may have more or fewer peanut plants than others. Samples from these subplots may bias the overall sample

Peanuts are planted on a 55-acre field. The field is divided into​ one-acre subplots. A sample is taken from each subplot to estimate the harvest. What is being used? Bias?

reasons for bias

Since the researcher knows which drug was applied to the​ patient, he/she may interpret the results in a different manner. There may be a bias on the part of the researcher in this case.

There is an association between U.S. women and being the primary investor in their household.

Suppose a survey of 558 women in the US found that more than 69% are the primary investor in their household. What is the best inference from the given information?

Census

The average salary of the 40 employees of a company. What would you use.. Census or sampling?

parameter

The average score for a class of 28 students taking a Calculus was 72%. What is the underlined value (72%)?

Ratio (horizontal represents cities by letters); vertical axis is also ratio and represents annual rainfall in inches by number.

The graph shows number of cities with certain average annual rainfall amounts (in inches). Identify the level of measurement of the data listed on the horizontal axis of the graph.

This is a population bc it is the number of floors in all buildings in the city.

The number of floors in each building in a city. Is this a population or sample?

Ordinal. The data can be arranged in order, but the differences between ranks is not meaningful.

The top five books on the best-seller list are shown below. What is the level of measurement for the data set?

Interval. The data can be ordered and differences between data entries are​ meaningful, but a zero entry is not an inherent zero.

The years that a tv show on a particular network won the Emmy for best drama series are shown below. What is the level of measurement of the data set?

ensures that each segment of the population is represented

What is an example of strata? Members of the population are divided into two or more​ subsets, called​ strata, that share a similar characteristic. The households sampled represent various​ locations, ethnic​ groups, and income brackets. Each of these variables is considered a stratum. Stratified sampling divides the population into subsets that share a similar characteristic. A sample is then randomly selected from each of the strata. What does Stratified sampling ensure?

It is impossible to gather information about the entire population of any country because the population is always changing.

Why is it impossible to gather info about the entire population?