Chapter 1 HW Questions

Determine whether the value given is from a discrete or continuous data set When a car is randomly selected, it is found to have a tire pressure of 28 psi

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

Identify the type of sampling used in the situation described below. In a poll conducted by a certain research center, 744 adults were called after their telephone numbers were randomly generated by a computer, and 31% were able to correctly identify the president.

Random Sampling

If we are collecting sample data for a study, the ___________ that we choose can greatly influence the validity of our conclusions. For example, We can use sound statistical methods to analyze data in voluntary response samples, but the results are not necessarily valid.

Sampling Method

Identify the type of sampling used in the situation described below. A researcher selects every 767th social security number and surveys the corresponding person.

Systematic Sampling

In a study of a sample of babies born at a hospital in one state, it was found that 48% of the babies were girls. Identify whether this value is a statistic or a parameter.

The value is a statistic because it describes some characteristic of a sample

Which of the following consists of discrete data? A. Hair color B. Number of suitcases on a plane C. Tree Height D. Amount of rainfall

B. Number of suitcases on a plane

Which of the following is associated with a parameter? A. Data that were obtained from a voluntary poll at the end of a service call B. Data that ere obtained from a sample C. Data that were obtained from an entire population D. A numerical measurement describing some characteristic of a sample

C. Data that were obtained from an entire population

Which of the following would be considered practically significant? A. 8 out of 14 births resulted in male children B. 1 out of 50 people were not smoking 12 months after completing a non-smoking program C. In a very large study, it was found that Treatment I resulted in 93% success while Treatment II resulted in 75% success D. An average of 1.2 pounds was lost over a 12 month period using a new diet program

C. In a very large study, it was found that Treatment I resulted in 93% success while Treatment II resulted in 75% success

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

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

Determine whether the results below appear to have statistical significance, and also determine whether the results have practical significance. One of a botanist's hybridization experiments with peas yielded 532 offspring with 136 of those peas (or 26%) having yellow pods. According to the genetic theory, 25% of the offspring peas should have yellow pods. Does the results have statistical significance? According to genetic theory, ______ of the 532 peas would have yellow pods. The difference between the actual number of peas with yellow pods and the expected number of peas with yellow pods is ____ peas. This difference ___________ (does/does not appear) to be statistically significant. Does the result have practical significance? The difference _____________ (does/does not appear) to have practical significance, because the actual number of peas with yellow pods and the expected number of peas with yellow pods is __________ (very small/large) compared to the actual number of peas with yellow pods.

133, 3, does not appear does not appear, very large

Which of the following would NOT cast doubt of the usefulness of sample data? A. An effective sampling method B. Missing data C. Nonresponse D. Order of questions in a survey

A. An effective sampling method

Which of the following would be classified as categorical data? A. Hair color B. Amount of rain C. Number of suitcases on a plane D. Tree Height

A. Hair color

Which of the following is NOT a voluntary response sample? A. Quiz scores from a college-level statistics course are analyzed to determine student progress B. A survey is taken at a mall by asking passersby if they will fill out the survey C. A radio station asks for call-in responses to a question concerning city recycling D. A local dentist asks her patients to fill out a questionnaire and mail it back to determine the quality of the care received during an office visit

A. Quiz scores from a college level statistics course are analyzed to determine student progress

In an AOL survey, these questions were posted online. "Have you ever been hit by a computer virus?" Among the 170,063 responses, 63% answered "yes". What term is used to describe this type of survey in which the people consist of those who chose to respond? What is wrong with this type of sampling method? What term is used to describe this type of survey? Select all that apply A. The respondents are a voluntary response sample B. The respondents are a self-selected sample C. The respondents are a census D. The respondents are a population What is wrong with this type of sampling method? Select all that apply A. Many people may choose not to respond to the survey B. The survey question is "loaded" or intentionally worded to elicit a desired response C. It is to time-consuming D. Responses may not reflect the opinions of the general population E. It is too expensive

A. and B. The respondents are a voluntary response sample The respondents are a self-selected sample A. and D. Many people may choose not to respond to the survey Responses may not reflect the opinions of the general population

Determine whether the sampling method described below appears to be sound or is flawed. In a survey of 588 subjects, the following question was posted on a newspapers website. "In your view, are nuclear plants safe?" The survey subjects were internet users who chose to respond to the question posted on the electronic edition of the newspaper. Chose the best answer A. It is flawed because it is a census B. It is flawed because it is a voluntary response sample C. It is flawed because it is not statistically significant D. It appears to be sound because the data are not biased in any way

B. It is flawed because it is a voluntary response sample

Survey questions may be misleading if they are "loaded". To what does "loaded" refer? A. Too much data B. Intentionally worded to elicit a desired response C. Questions that trigger a nonresponse D. Not concise; very long drawn out questions

B. Intentionally worded to elicit a desired response

Which of the following is NOT a misuse of statistics? A. Concluding that a variable causes another variable because they have some correlation B. Utilizing valid statical methods and correct sampling techniques C. Making conclusions about a population based in a voluntary response sample D. Misleading graphs

B. Utilizing valid statical methods and correct sampling techniques

Identify the type of sampling used in the situation described below. To determine customer opinion of their safety features, Daimler-Chrysler randomly selects 60 service centers during a certain week and surveys all customers visiting the service centers.

Cluster

Which sampling method divides the population into sections, randomly selects some of the sections, then chooses all the members from the selected sections to study?

Cluster

Identify the type of sampling used in the situation described below. A newspaper ask its readers to call in their opinion regarding their taste in reading.

Convenience

Which of the following is NOT a level of measurement? A. Nominal B. Ratio C. Ordinal D. Quantitative

D. Quantitative

What does it mean for the findings of a statistical analysis of data to be statistically significant? A. The results do not make enough difference to be of use B. The results are very important to the health and well-being of a certain population C. The outcome could easily occur by chance D. The likelihood of getting these results by chance is very small

D. The likelihood of getting these results by chance is very small

Determine whether the results below appear to have statistical significance, and also determine whether the results have practical significance. In a study of a weight loss program, 4 subjects lost an average of 48 lbs. It is found that there is about a 20% chance of getting such results with a diet that has no effect. Does the weight loss program have statistical significance? Does the weight loss program have practical significance?

No, the program is not statistically significant because the results are likely to occur by chance Yes, the program us practically significant because the amount of weight loss is large enough to be considered practically significant

Which of the following corresponds to the case when every sample of size n has the same chance of bein chosen?

Simple random sample

Determine whether the underline number is a statistic or a parameter. A sample of seniors is selected and it is found that 25% own a computer.

Statistics, because the value is a numerical measurement describing a characteristic of a sample

Identify the type of sampling used in the situation described below. To determine her breathing rate, Britney divides up her day into 3 parts: morning, afternoon, night. She then measures her breathing rate at 2 randomly selected times during each part of the day.

Stratified

Which sampling method subdivided the population into categories sharing similar characteristics and then selects a sample from each subdivision>

Stratified

Identify the type of sampling used in the situation described below. A man experienced a tax audit. The tax department claimed that the man was audited because every 10,000th person on the taxpayer list was being audited.

Systematic Sampling

State whether the data below are discrete or continuous, and explain why. The numbers on tv in different households

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