Q&A Hero

Q: It is possible for the same survey questionnaire to yield both quantitative and qualitative data.

Q: When students are asked to list their age and the percentage of their college expenses that they pay for themselves, the type of data being collected is quantitative.

Q: The sales data for a company measured weekly for the past year would be considered cross-sectional data since the sales values are computed from the entire company.

Q: If a population is very large, it may be better to select a sample from the population than to try to obtain a census in an effort to reduce measurement error.

Q: A market research firm that surveys customers in a shopping mall by asking various people to respond to a short survey about a new product is performing convenience sampling.

Q: One of the reasons that managers prefer statistical sampling to nonstatistical sampling is that statistical sampling is generally easier to perform and less expensive.

Q: Suppose a professor collects survey data by passing out surveys in his/her classes, where the population of interest is defined as all students enrolled at that university. This is an example of nonstatistical sampling technique.

Q: When a small sample is used, a stratified random sample is more likely to provide the desired information than a simple random sample.

Q: Stratified random sampling is the same thing as simple random sampling.

Q: If a state agency wishes to conduct on-site surveys of small businesses throughout the state, cluster sampling could potentially be used to reduce the geographical area over which the surveys would need to be conducted.

Q: In election years, the polls that are conducted by such companies as Gallup and Harris typically employ stratified random sampling to reduce the number of people that will need to be surveyed.

Q: When stratified random sampling is employed, the population is divided into homogeneous subgroups called strata.

Q: Simple random sampling involves selecting members of the population in such as way that all members are equally likely to be chosen.

Q: A common underpinning of all statistical sampling techniques is the concept of random selection.

Q: Possibly the most frequently used nonstatistical sampling procedure is the simple random sample.

Q: One of the most common statistical sampling techniques is convenience sampling.

Q: It is possible for a nonstatistical sample to yield statistics that have values closer to the corresponding parameter than will a statistical sample.

Q: A pharmaceutical company conducts a study where 50 patients are given a drug. They find that 10 percent of patients experience nausea as a side effect. This 10 percent is an example of a parameter.

Q: When a group of university students takes a poll of their fellow students on whether they support a proposed fee increase, the sampling method they would use when students walking near the library are surveyed would be called a random sample.

Q: If an analyst computes statistics from a sample, the sample is by definition a statistical sample.

Q: The First National Bank mailed out a survey to all 3,456 savings account customers. A total of 568 surveys were returned. Values computed from the returned surveys would constitute parameters since all 568 customers were surveyed.

Q: When the production manager selects a sample of items that have been produced on her production line and computes the proportion of those items that are defective, the proportion is referred to as a statistic.

Q: Statistics are measures computed from the entire population of data.

Q: Population parameters are descriptive numerical measures, such as an average, that describe the entire population.

Q: A parameter is the boundary on the population of interest.

Q: A sample is selected from a population in cases where selecting data from the entire population is either very difficult or very expensive.

Q: A census is an enumeration of the entire sample of items selected from the population of interest.

Q: When the marketing manager for a large company surveys a portion of the total customers of his company, he is using a sample from the population.

Q: When the United States conducts a census that counts all people in the country, this is an example of using a sample.

Q: Recently, an analyst in a company's marketing department surveyed customers regarding how often they buy a particular product. One customer indicated that she purchased the product 17 times in the last six months, but the analyst recorded the response as 71 times. This is an example of observer bias.

Q: Selection bias occurs when the respondent decides which of the questions on the survey to answer.

Q: When people fail to respond to a survey, the data collection process may suffer from nonresponse bias.

Q: It is possible for an interviewer to interject bias into the data collection project by the way he or she asks the questions.

Q: Data collected on the Internet can generally be considered accurate since the data must go through a screening process before they can be placed on the Internet.

Q: When a company scans the bar codes on its products in an effort to count the number of products that remain in inventory, the company is collecting data through experimentation.

Q: When a survey is done you can always assume that non-respondents would have answered the same way as those who did respond.

Q: Data gathered from a structured interview is generally easier to analyze than data collected from an unstructured interview.

Q: The method of data collection called direct observation is always associated with gathering data from people.

Q: Open-end questions are typically included in a survey when the objective is to provide the maximum opportunity for the respondent to express his or her opinion.

Q: Questions on a written survey dealing with the characteristics of the respondent (age, income, etc.) are referred to as categorical questions.

Q: Close-end questions provide the greatest opportunity to obtain ideas and thoughts on the part of those surveyed but the resulting data are more difficult to analyze.

Q: The primary purpose of performing a pre-test when developing a telephone or mail survey is to make sure that the respondents can understand the questions and are able to provide meaningful responses.

Q: One of the advantages of data check sheets is that as the data are being recorded, they are also being displayed in a useful format.

Q: Data collected using open-end questions is generally easier to analyze than data collected from closed-end questions.

Q: A company that is interested in determining which of three prices to charge for its products has test marketed the product in three cities, each time using a different price for the product. The number of products sold in the first week is recorded. In this case, the data are considered to have been collected using an experiment.

Q: When an interviewer asks a specified series of questions in the course of a personal interview, he/she is conducting an unstructured interview.

Q: On a survey, the questions pertaining to the background of the respondent (age, gender, etc.) are referred to as demographic questions.

Q: One way to improve the response rate for a survey is to administer the surveys directly to the respondents.

Q: In an unstructured interview the questions are scripted.

Q: Mail questionnaires typically generate poor response rates.

Q: Assuming that you are planning to collect data using an experiment, it will be very important to establish an appropriate survey design.

Q: When comparing experiments, surveys, and direct observation as methods of data collection, the method that would typically be the least expensive is surveys.

Q: The Georgia Company, a pharmaceutical company, recently conducted a study in which 20 people were given a new drug and 20 other people were given a placebo. The objective was to determine whether there was a difference in pain relief between those using the new drug versus those using the placebo. The data collection used here is an example of an experiment.

Q: The Cranston Company recently met with a group of its customers to ask questions about the service and products provided by the company. The data collected in this process would be an example of data collected through direct observation.

Q: A short survey with closed-end questions is likely to have a better response rate than a long survey with open-ended questions.

Q: An open-end question requires respondents to choose from a short list of choices

Q: An Internet-based or emailed survey is not an alternative method of data collection.

Q: Typically, it is possible to include a larger number of questions in a phone survey than in a mail survey since it takes less time to complete the survey over the phone.

Q: Experimental design is a plan for performing an experiment where the effects of one or more factors on the variable of interest are measured.

Q: An experiment is a process that generates data as its outcome.

Q: Some of the most common methods of collecting data include experiments, telephone surveys, mail questionnaires, direct observations, and personal interviews.

Q: A sales manager has five salespeople. The following are the number of units sold by the five salespeople during the past week: {5, 13, 6, 2, 4}. Based on the data, the mean number of units sold was 6 units.

Q: A light bulb manufacturer wants to advertise the average life of its light bulbs so it tests a subset of light bulbs. This is an example of inferential statistics.

Q: Statistical inference would be used as the primary statistical tool by a quality control manager who wishes to estimate the average weight of her company's products.

Q: Another term for the arithmetic average is the mean.

Q: Hypothesis testing and estimation are two statistical tools that are used to draw inferences about a large data set based on a subset of the data.

Q: The editor of a local newspaper is interested in determining the percentage of subscribers who read the paper's editorials. The statistical technique that he would use is called estimation.

Q: An accountant who recently examined 200 accounts from a company's total of 4,000 accounts in an effort to estimate the percentage of all accounts that have incorrect journal entries is using descriptive statistical analysis to reach the conclusion.

Q: A manufacturing manager has developed a table that shows the average production volume each day for the past three weeks. The average production level is an example of a numerical measure.

Q: Companies frequently use charts and graphs in their regular communications with stockholders and investors; this shows the use of descriptive statistics.

Q: A histogram is an example of a numerical measure.

Q: Descriptive statistical tools include graphs, charts, and numerical measures.

Q: An accountant has recently prepared a report for a client that contains a variety of graphs and charts. In doing so, she has used descriptive statistical methods.

Q: Descriptive statistics allow a decision maker to reach a conclusion about a population based on a subset from the population.

Q: In this course, the term business statistics refers to the set of tools and techniques that are used to convert information into meaningful data.

Q: Statistics is a discipline that involves tools and techniques used to describe data and draw conclusions.

Q: Ledd Electronics has received a large shipment of power supply units for the desktop computers being assembled. The units are coming from a new supplier and Ledd is not sure what the actual defect rate will be for this component. Ledd is considering an acceptance sampling plan with n= 30 and c= 1.a. Find the probability of accepting a lot when the defect rate is 2%, 4%, and 6%.b. What happens to the producer's risk as the defect rate increases?c. What happens to the consumer's risk as the defect rate increases?

Q: An acceptance sampling plan with n= 20 and c= 1 has been designed with a producer's risk of .12.a. Was the value of p0equal to .02, .03, .04, or .05?b. What is the consumer's risk associated with this plan if p1is .08?c. Assume the consumer's risk found in (b) is unacceptably high. Which modification of the sampling plan will result in the greater reduction of the consumer's risk, increasing nto 30 or decreasing cto 0?

Q: A process that is in control has a mean of = 56.5 and a standard deviation of = 3.4. What should the control limits be for a sample mean chart if samples of size 8 are taken?

Q: A process sampled 30 times with a sample of size nine resulted in = 12.7 and = 0.8. Compute the upper and lower control limits for the and charts for this process.