Question 1

A manufacturer of televisions claims that fewer than 3% of their products are defective. When 100 televisions were drawn from a large production run, 10% were found to be defective.
A.What is the population of interest?
B.What is the sample?
C.What is the parameter?
D.What is the statistic?
E.Does the value of 3% refer to the parameter or the statistic?
F.Is the value of 10% a parameter or a statistic?
G.Explain briefly how the statistic can be used to make inferences about the parameter to test the claim.

Accepted Answer

A. The complete production run of the manufacturer.
B. The 100 televisions selected.
C. The proportion of the production run that is defective.
D. The proportion of the sample televisions that is defective.
E. Parameter.
F. Statistic.
G. Because the sample proportion is more than 3%, we conclude that the sample data selected does not support the claim.

Question 2

Descriptive statistics deals with methods of:

Accepted Answer

Descriptive statistics involves all three methods: organising, summarising, and presenting data in an informative way. Therefore, the correct answer is D, that is, all of these choices are correct.

Question 3

Consider the population of all pencil manufacturers in the world. Describe any four examples of possible samples that could be taken from this population.

Accepted Answer

-Manufacturers of wooden pencils.
-Manufacturers of colour pencils.
-Manufacturers of graphite pencils.
-Australian manufacturers of pencils.

Question 4

Which of the following statements is true?

Accepted Answer

Descriptive statistics can use both graphical and numerical techniques to describe and summarize data. Statistical inference is used to draw conclusions about a population based on a sample of data.

Question 5

Which of the following is the goal of descriptive statistics?
A.To summarise data.
B.To display aspects of the collected data.
C.To summarise data and display aspects of the collected data.
D.To estimate characteristics of the population.

Accepted Answer

The answer of Which of the following is the goal...

Question 6

A summary measure that is computed from a population is called:

Accepted Answer

A parameter is a summary measure that is computed from a population. A statistic, on the other hand, is a summary measure computed from a sample. A sample is a subset of a population. Therefore, only choice A is correct.

Question 7

A politician who is running for the House of Representatives in the Australian Federal parliament with 70,000 registered voters in her electorate commissions a survey. In the survey, 52% of the 300 registered voters interviewed say they plan to vote for her. The sample is the:

Accepted Answer

The sample is the 300 registered voters interviewed for the survey, not the entire population of 70,000 voters or just the percentage who plan to vote for the politician. Option B refers only to the subset of the sample who plan to vote for the politician, while option D refers to the subset who do not plan to vote for her.

Question 8

A summary measure that is computed from a population is called a population parameter.

Accepted Answer

This statement is correct, a population parameter is a summary measure computed from an entire population.

Question 9

You ask five of your classmates about their height. On the basis of this information, you state that the average height of the students in the sample is 170 cm. Which of the following is this an example of?

Accepted Answer

Descriptive statistics involves describing or summarizing a sample or population without making any inferences or generalizations about the larger population. In this case, calculating the average height of the five classmates is an example of a descriptive statistic.

Question 10

Define each of the following statistical terms:
A.Descriptive statistics.
B.Statistical inference.
C.Population.
D.Sample.
E.Parameter.F.Statistic.

Accepted Answer

The answer of Define each of the following statistical terms:
A.Descriptive...

Question 11

A local cable TV system using a sample of 500 subscribers finds that 40% of these subscribers watch a premium channel at least once per day. This is an example of statistical inference as opposed to
descriptive statistics.

Accepted Answer

This is an example of descriptive statistics because it describes data collected from a sample (the 40% of subscribers watching a premium channel) without making inferences about a larger population.

Question 12

Statistical inference is the process of making an estimate, prediction or decision about a population, based on sample data.

Accepted Answer

Statistical inference involves using sample data to draw conclusions or make predictions about a population. It is an important tool in many fields, including scientific research, business, and economics.

Question 13

A businessman who is running for a vacant city council seat with 2000 registered voters conducts a survey. In the survey, 200 of the 300 registered voters interviewed say they plan to vote for him.
A.What proportion of the respondents plans to vote for this businessman?
B.What is the population of interest?
C.What is the sample?
D.Is your answer in part A above a parameter or a statistic?

Accepted Answer

The answer of A businessman who is running for a...

Question 14

A summary measure that is computed from a sample to describe a characteristic of the population is called a statistic.

Accepted Answer

This is a correct definition of a statistic.

Question 15

A summary measure that is computed from a sample to describe a characteristic of the population is called:

Accepted Answer

A summary measure computed from a sample is a statistic, while a parameter is a summary measure calculated from a population. A population is the entire collection of individuals or items that the researcher is interested in studying. Therefore, the correct answer is B - a statistic.

Question 16

Which of the following best describes the data that is collected in a statistical study for only a portion or subset of all elements of interest?

Accepted Answer

When data is collected for only a portion or subset of all elements of interest, it is called a sample. A census would involve collecting data from every single element or individual in the population, while a population is the entire group of interest. A parameter is a numerical value that describes a characteristic of the population, but it is not the data that is collected.

Question 17

Identify each of the following studies as using either descriptive statistics or inferential statistics.
A.Calculating the relative frequency of Holden Commodore SV6 cars passing by your house
between 7pm and 8pm this evening.
B.Estimating the proportion of households in Melbourne that have at least two dependents, from a random sample of 100 Melbournian households.
C.Measuring the fuel efficiency of five brand new Holden Commodore SV6 cars in order to find out whether the average fuel consumption of this make and model is better than 10L/100km.
D.Calculating the proportion of female students in a business statistics class.
E.Estimating the average age of students at La Trobe University from a sample of 200 randomly
selected students.

Accepted Answer

The answer of Identify each of the following studies as...

Quiz 1: What Is Statistics