Elementary Statistics Homework, Quizzes, and Exams

State whether the data described below are discrete or​ continuous, and explain why. The maximum capacities of various stadiums

The data are discrete because the data can only take on specific values.

Determine whether the value given below is from a discrete or continuous data set. When a car is randomly selected and weighed, it is found to weigh 1851.5 kg.

A continuous data set because there are infinitely many possible values and those values cannot be counted.

Determine whether the value given below is from a discrete or continuous data set. In a test of a method of gender selection comma 674 couples used the XSORT method and 537 of them had baby girls.

A discrete data set because there are a finite number of possible values.

Which of the following is associated with a​ parameter?

A parameter is a numerical measurement describing some characteristic of a population.​ So, a parameter is associated with data that were obtained from an entire population.

Identify the type of observational study​ (cross-sectional, retrospective, or​ prospective) described below. A research company uses a device to record the viewing habits of about 15 comma 000 ​households, and the data collected over the past 4 years will be used to determine whether proportion of households tuned to a particular news program increased.

A retrospective study

Identify which type of sampling is​ used: random,​ systematic, convenience,​ stratified, or cluster. To determine customer opinion of their check dash in service​, American Airlines randomly selects 30 flights during a certain week and surveys all passengers on the flights.

Cluster

Which of the following is associated with a​ parameter?

Data that were obtained from an entire population

Determine whether the value is from a discrete or continuous data set. Number of bacteria in a petri dish is 12,120

Discrete

Determine whether the description corresponds to an observational study or an experiment. Eighty patients with stomach cancer are divided into two groups. One group receives an experimental drug to fight cancer, the other a placebo. After one year, the spread of the cancer is measured.

Experiment

Determine whether the given value is from a discrete or continuous data set. When a car is randomly​ selected, it is found to have an engine with 4 cylinders.

It is from a discrete data set because the number of possible values is finite or countable.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. States in a region

Nominal

A study is conducted to measure​ children's growth rates without any treatment applied to the children. What best classifies this​ study?

Observational study

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Rankings of musicians

Ordinal

Identify the type of sampling used​ (random, systematic,​ convenience, stratified, or cluster​ sampling) in the situation described below. In a poll conducted by a certain research​ center, 1228 adults were called after their telephone numbers were randomly generated by a​ computer, and 93 % were able to correctly identify the attorney general.

Random Sampling

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Ages of children: 5, 6, 7, 8, and 9

Ratio

Determine whether the given value is a statistic or a parameter. A sample of professors is selected and it is found that 35% own a vehicle.

Statistic because the value is a numerical measurement describing a characteristic of a sample

State whether the data described below are discrete or​ continuous, and explain why. The number of loans a bank makes each month. The number of loans a bank makes each month nothing

The data are discrete because the data can only take on specific values.

Determine whether the data described below are qualitative or quantitative and explain why. The styles of shoes of clients entering a certain store (sneaker, boot, sandal, etc.)

The data are qualitative because they don't measure or count anything.

Which level of measurement consists of categories only where data cannot be arranged in an ordering​ scheme?

The nominal level of measurement is characterized by data that consist of​ names, labels, or categories only. The data cannot be arranged in an ordering scheme​ (such as low to​ high).

Which of the following consists of discrete​ data?

The number of suitcases on a plane is a number representing a count. This would consist of discrete data.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Ranks of cars evaluated by a consumer's magazine

The ordinal level of measurement is most appropriate because the data can be ordered, but differences cannot be found or are meaningless.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Bushels of wheat

The ratio level of measurement is most appropriate because the data can be ordered, differences (obtained by subtraction) can be found and are meaningful, and there is a natural starting zero point.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate. Miles of road

The ratio level of measurement is most appropriate because the data can be ordered, differences can be found and are meaningful, and there is a natural starting zero point.

Determine whether the given value is a statistic or a parameter. A survey found that 30 % of all respondents go to school.

The value is a statistic because it is a numerical measurement describing some characteristic of a sample.

Identify the type of observational study. Upper A researcher plans to obtain data by interviewing relatives of victims who perished in a bombing to see how they're coping now.

cross-sectional

Determine whether the given value is a statistic or a parameter. Upper A sample of seniors is selected and it is found that 45% own a vehicle.

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 students is selected and it is found that 50 % own a computer.

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

Identify which of these types of sampling is​ used: random,​ systematic, convenience,​ stratified, or cluster. To determine her mood​, Britney divides up her day into three​ parts: morning,​ afternoon, and evening. She then measures her mood at 2 randomly selected times during each part of the day.

Stratified

Which sampling method subdivides the population into categories sharing similar characteristics and then selects a sample from each​ subdivision?

Stratified

Identify which of these types of sampling is​ used: random,​ systematic, convenience,​ stratified, or cluster. Upper A market researcher has partitioned all residents of a certain region into categories of young left parenthesis age 0 dash 30 right parenthesis comma middle aged left parenthesis age 31 dash 60 right parenthesis comma and senior left parenthesis over age 60 right parenthesis . She is surveying 49 people from each category.

Stratified Sampling

In a​ survey, the responses of respondents are identified as 10 for a "yes", 20 for a "no", 30 for a "maybe", and 40 for anything else. The average​ (mean) is calculated for 715 respondents and the result is 22.3. Identify the level of measurement of the​ data. Explain what is wrong with the given calculation.

The data are at the nominal level of measurement. Such data are not counts or measures of​ anything, so it makes no sense to compute their average​ (mean).

In a set of​ data, blood lead levels are represented as 10 for low, 20 for medium, and 30 for high. The average​ (mean) of the 529 blood lead levels is 25.4. Identify the level of measurement of the​ data. Explain what is wrong with the given calculation.

The data are at the ordinal level of measurement. Such data should not be used for calculations such as an average.

State whether the data described below are discrete or continuous, and explain why: The temperatures (in degrees Fahrenheit) of pizzas fresh the from oven

The data are continuous because the data can take any value in any interval

State whether the data described below are discrete or​ continuous, and explain why. The heights of trees in a forest

The data are continuous because the data can take on any value in an interval.

Determine which of the four levels of measurement​ (nominal, ordinal,​ interval, ratio) is most appropriate for the data below. Ratings of novels

The ordinal level of measurement is most appropriate because the data can be ordered, but differences left parenthesis obtained by subtraction right parenthesis cannot be found or are meaningless.

Determine if the following statement represents a meaningful​ ratio, so the ratio level of measurement applies. A movie with a​ 4-star rating is twice as good as one with a​ 2-star rating

The ratio level of measurement does not apply.

A particular country has 45 total states. If the areas of 20 states are added and the sum is divided by 20​, the result is 186 comma 979 square kilometers. Determine whether this result is a statistic or a parameter.

The result is a statistic because it describes some characteristic of a sample.

Determine whether the study is an experiment or an observational​ study, and then identify a major problem with the study. A study involved​ 22,071 male physicians. Based on random​ selections, 11,037 of them were treated with aspirin and the other​ 11,034 were given placebos. The study was stopped early because it became clear that aspirin reduced the risk of myocardial infarctions by a substantial amount.

This is an experiment because the researchers apply a treatment to the individuals. The results apply only to male physicians