Ch. 1 Stats review

Why is a sample used more often than a​ population?

• Sample statistics are more accurate than the population parameter.

• It is usually impossible to count the entire population.

• All samples are representative of a​ population, so the population does not need to be used.

• Inferences cannot be made when using the population.

Determine whether the statement is true or false. If it is​ false, rewrite it as a true statement.

A population is the collection of some​ outcomes, responses,​ measurements, or counts that are of interest.

• True.

• False. A sample is the collection of all​ outcomes, responses,​ measurements, or counts that are of interest.

• False. A population is the collection of all​ outcomes, responses,​ measurements, or counts that are of interest.

Determine whether the following statement is true or false. If it is​ false, rewrite it as a true statement.

A sample statistic will not change from sample to sample.

• The statement is false. A sample parameter will not change from sample to sample.

• The statement is false. A sample statistic can change from sample to sample.

• The statement is false. A population statistic will not change from population to population.

• The statement is true.

Determine whether the data set is a population or a sample. Explain your reasoning.

The heights of half of the

students in a class.

• Sample, because it is a collection of heights for all of the students in the class, but there are other classes.

• Population, because it is a subset of all students in the class.

• Sample, because the collection of heights of half of the students is a subset of all students in the class.

• ​Population, because it is a collection of heights for all of the students in the class.

Determine whether the data set is a population or a sample. Explain your reasoning.

The number of cars for 10 households in a neighborhood of 30 households.

• Sample, because the collection of the number of cars for 10 households is a subset of all households in the neighborhood.

• Sample, because it is a collection of the number of cars for all households in the neighborhood, but there are other neighborhoods.

• Population, because it is a collection of the number of cars for all households in the neighborhood.

• Population, because it is a subset of all households in the neighborhood.

Identify the population.

A survey of 147 law firms in a country found that the average hourly billing rate for partners was ​$628.

• the law firms that were surveyed

• all partners

• all people in the country

• all law firms in the country

A survey of 147 law firms in a country found that the average hourly billing rate for partners was ​$628.

Identify the sample.

• all law firms in the country

• the law firms that were surveyed

• all people in the country

• all partners

A survey of 147 law firms in a country found that the average hourly billing rate for partners was ​$628 per hour.

Identify the sample data set.

• Charging an average of ​$628 per hour

• The average hourly billing rate for partners of 147 law firms was ​$628.

• Partners of 147 law firms were billed exactly ​$628 per hour.

• The 147 law firms

A survey of 1010 parents of​ 13- to​ 17-year-olds found that 627 of the 1010 parents have checked their​ teen's social media profile.

Identify the population.

• The collection of responses of the 1010 parents of​ 13- to​ 17-year-olds surveyed

• The collection of responses of all parents

• The collection of responses of parents of​ 13- to​ 17-year-olds

• The collection of responses of the 627 parents of​ 13- to​ 17-year-olds who said they have checked their​ teen's social media profile

A survey of 1010 parents of​ 13- to​ 17-year-olds found that 627 of the 1010 parents have checked their​ teen's social media profile.

Identify the sample.

• The collection of responses of the 1010 parents of​ 13- to​ 17-year-olds surveyed

• The collection of responses of parents of​ 13- to​ 17-year-olds

• The collection of responses of the 627 parents of​ 13- to​ 17-year-olds who said they have checked their​ teen's social media profile

• The collection of responses of all parents