Stascs Updated - (Solutions Manual All Chapters, 100% Original V...

Sta�s�cs Updated Edi�on 13e James McClave, Terry Sincich (Solutions Manual All Chapters, 100% Original Verified, A+ Grade) 1 / 4

Statistics, Data, and Statistical Thinking 1 Copyright © 2017 Pearson Education, Inc.Statistics, Data, and Statistical Thinking 1.2 Descriptive statistics utilizes numerical and graphical methods to look for patterns, to summarize, and to present the information in a set of data. Inferential statistics utilizes sample data to make estimates, decisions, predictions, or other generalizations about a larger set of data.

1.4 The first major method of collecting data is from a published source. These data have already been collected by someone else and is available in a published source. The second method of collecting data is from a designed experiment. These data are collected by a researcher who exerts strict control over the experimental units in a study. These data are measured directly from the experimental units. The third method of collecting data is from a survey. These data are collected by a researcher asking a group of people one or more questions. Again, these data are collected directly from the experimental units or people. The final method of collecting data is observationally. These data are collected directly from experimental units by simply observing the experimental units in their natural environment and recording the values of the desired characteristics.

1.6 A population is a set of existing units such as people, objects, transactions, or events. A variable is a characteristic or property of an individual population unit such as height of a person, time of a reflex, amount of a transaction, etc.

1.8 A representative sample is a sample that exhibits characteristics similar to those possessed by the target population. A representative sample is essential if inferential statistics is to be applied. If a sample does not possess the same characteristics as the target population, then any inferences made using the sample will be unreliable.

1.10 Statistical thinking involves applying rational thought processes to critically assess data and inferences made from the data. It involves not taking all data and inferences presented at face value, but rather making sure the inferences and data are valid.

1.12 a. High school GPA is a number usually between 0.0 and 4.0. Therefore, it is quantitative.

b.High school class rank is a number: 1st, 2nd, 3rd, etc.

Therefore, it is quantitative.c.The scores on the SAT's are numbers between 200 and 800. Theref ore, it is quantitative.

• Gender is either male or female. Therefore, it is quali

tative.e.

Parent's income is a number: $25,000, $45,000,

etc. Therefore, it is quantitative.f.

Age is a number: 17, 18, etc. Therefore, it is quantita

tive.

1.14 a. The experimental unit for this experiment is a drafted NFL quarterback.b.Draft position is one of three categories.Therefore, it is a qualitative variable. NFL winning ratio is a number. Therefore, it is a quantitative variable. QB production score is a number.Therefore, it is a quantitative variable.Chapter

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Copyright © 2017 Pearson Education, Inc.c.Because all quarterbacks drafted over a 38-year period were used, the application of this study is descriptive statistics.

1.16 a. The variable “difference between before and after sprint times” is measured in seconds.Thus, it is quantitative. The variable “improvement” is measured as one of three categories. Thus, it is qualitative.b.The data set is a sample. It contains observations from only 14 of all high school foot ball players.

1.18 a. The population of interest is all the students in the class. The variable of interest is the GPA of a student in the class.b.Since GPA is measured on a num erical scale, it is quantitative.c.Since the population of interest is all the students in the class and you obtained th e GPA of every member of the class, this set of data would be a census.d.Assuming the class had more than 10 studen ts in it, the set of 10 GPAs would represent a sample. The set of ten students is only a subset of the entire class.e.This average would have 100% reliability as an "estimate" of the class average, since it is the average of interest.f.The average GPA of 10 members of the class will not necessarily be the same as the average GPA of the entire class. The reliability of the estimate will depend on how large the class is and how representative the sample is of the entire population.g.In order for the sample to be a random sample, every member of the class mu st have an equal 1.20 a. Flight capability can have only 2 possible outcomes: volant or flightless. Thus, it is qualitative.

• Habitat type can have only 3 possible outcomes: aquatic, ground terrestrial, or aer

ial terrestrial. Thus, it is qualitative.c.

Nesting site can have only 4 possible outcomes: ground, cavity within ground,

tree, or cavity above ground. Thus, it is qualitative.d.Nest density can have only 2 possible outcomes: high or low. Thus, it is qualitati ve.e.

Diet can have only 4 possible outcomes: fish, vertebrates, vegetables

, or invertebrates.Thus, it is qualitative.f.Body mass is measured in grams, a meaningful number. Thus, it is quantitative.g.Egg length is measured in millimeters, a meaningful number. Thus, it is quantitati ve.h.Extinct status can have only 3 possible outcomes: extinct, absent from island, or present.Thus, it is qualitative. 3 / 4

Statistics, Data, and Statistical Thinking 3

Copyright © 2017 Pearson Education, Inc.

1.22 a. The population of interest to CSI is all computer security personnel at all U.S.corporations and government agencies.

• The data collection method is a survey. A survey was sent to 5,412 firms with 351 firms

responding.

• The variable collected was whether or not the respondents admitted unauthorized use of

computer systems at their firms during the year. Since the response to the questions was either “yes” or “no”, this variable is qualitative.

• In the sample 41% of the respondents admitted unauthorized use of computer systems at

their firms during the year. If there is no nonresponse bias, then we can conclude that 41% of all firms would admit to unauthorized use of computer systems at their firms during the year.

1.24 The following variables would be qualitative because the response would be a category: country of operator/owner, primary use, and class of orbit. The following variables would be quantitative because the response would be a number: Longitudinal position, apogee, launch mass, usable electric power, and expected lifetime.

1.26 a. The population of interest is all senior managers at CPA firms.

• The data collection method used is a survey.

• Because only 992 of the 23,500 surveys sent out were returned and useable, there may be

a problem with selection bias and/or nonresponse bias.

• The validity of the inferences drawn from the study would be suspect. The inferences

would only be valid if the 992 returned surveys were indeed, representative of the entire population. This is very unlikely.

1.28 a. The experimental unit for this study is a single-family residential property in Arlington, Texas.

• The variables measured were the Zillow estimated value and the actual sale price. Both

are quantitative variables.

• If the population was described as all single-family residential properties in Arlington,

Texas that sold within a given time period, then these 2,045 single-family residential properties could be the population if these were the only single-family residential property sales in Arlington, Texas in that time period.

• The population could be all single-family residential properties sold in Arlington, Texas

in a given time period and these 2,045 single-family residential properties did not include all the properties sold.

• No. The single-family residential properties sold in Arlington, Texas probably are not

similar to all single-family residential properties sold in the United States. Single-family residential properties sold in Arlington, Texas are not similar to single-family residential properties sold in places like New York City or San Francisco, California.

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