Brase and Brase - Understandable Statistics 13/e

1. 3/4 points | Previous Answers BBUnderStat13 7.CE.002.SIP. My Notes

This exercise will gain student interest.
Stats in Practice video questions show your students how statistics is applied in the real world with short news videos introducing each chapter followed by multiple-choice and discussion questions.

Stats in Practice

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2. 5/20 points | Previous Answers BBUnderStat13 6.3.SYS.002.S. My Notes

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This exercise will gain student interest.
Select Your Scenario questions provide students with 3 different contexts to choose from. Students select the scenario most relevant to them, and then solve the problem which requires them to answer questions demonstrating knowledge of a learning objective.

Instructions

Select Your Scenario:

This problem contains data for 3 different scenarios: Travel and Tourism, Business, and Sports.

Read the scenarios, and once finished, you will be asked to select which scenario you would like to be assessed on.

You will not be asked to answer questions for the other 2 scenarios.

Travel and Tourism

When you travel by airplane, have you ever wondered about whether your flight might be delayed from taking off or from landing? This is an important consideration as you will need to arrange transportation to your final destination after you arrive at the airport. To help track airline performance, the U.S. Bureau of Transportation Statistics of the Department of Transportation publishes statistics. For the purposes of this dataset, a flight is considered delayed if it arrived at (or departed from) the gate 15 minutes or more after the scheduled arrival (or departure) time as reflected in the Computerized Reservation System.

We will explore the distribution of monthly percentage of domestic flights delayed in the United States using a sample of data for the years 2010 through 2019 by making a histogram with bins starting at 9% and a bin width of 3%. We will then determine the z-scores for a delayed percentage of (a) 14% and (b) 25%.

The dataset consists of the percentage of flights delayed for each month for years 2010 through 2019 for domestic flights in the United States.

†Airline Performance: Bureau of Transportation Statistics. (2020, September 1). On-Time Performance - Flight Delays at a Glance. United States Department of Transportation. https://www.transtats.bts.gov/HomeDrillChart.asp
Year	Month	Delayed (%)
2010	January	18.58
2010	February	19.66
2010	March	18.3
2010	April	13.83
2010	May	18.55

Business

Undergraduate business students at a public university in the midwestern United States ran a café one semester and collected data each business day to help make sound business decisions and to be more profitable. Among other things, the daily total cash register sales were recorded.

We will explore the distribution of daily total sales for this café using a sample of data from one semester by making a histogram of Sales ($) with bins starting at $60 and a bin width of $25. We will then determine the z-scores for a day when total sales were (a) $195 and (b) $90.

The dataset consists of data recorded across one semester including an index number that puts the observations in chronological order, the day of the week, and the total sales in dollars.

†http://jse.amstat.org/jse_data_archive.htm
Index	Day of Week	Sales($)
1	Tuesday	199.95
2	Wednesday	195.74
3	Thursday	102.68
4	Friday	162.88
5	Monday	101.76

Sports

It goes without saying that professional basketball players are tall. Height obviously matters when it comes to playing basketball and tall people are more efficient because they can reach the basket easily, allowing for more points per game, as well as more rebounds and blocked shots. If you watch National Basketball Association (NBA) games regularly, you certainly notice that many players are quite tall.

We will explore the distribution of NBA player heights using a sample of players active in the 2019-2020 season by making a histogram of "HEIGHT (INCHES)" with bins stating at 68 inches and a bin width of 2 inches. We will then determine the z-scores for players who are (a) 71 inches (5'11") and (b) 83 inches (6'11").

The dataset consists of the NBA player's name, team, and height, measured in inches, for players active in the 2019-2020 season.

†https://www.nba.com/stats/players/bio/
Player	Team	Height (Inches)
Aaron Gordon	ORL	80
Aaron Holiday	IND	73
Abdel Nader	OKC	77
Adam Mokoka	CHI	77
Admiral Schofield	WAS	77

Click the link below to begin the question by choosing a topic.

Pick your topic.

Choose the topic on which you would like to be assessed. Once you select your scenario, you cannot change your topic.

Travel and Tourism correct

Business Sports

Note: If you select Skip, you will be assessed on the Travel and Tourism topic.

Instructions

Select Your Scenario:

First, select the tab that corresponds to the topic you chose above.

Note: Click the SALT button in the tab corresponding to the topic you chose.

Travel and Tourism

When you travel by airplane, have you ever wondered about whether your flight might be delayed from taking off or from landing? This is an important consideration as you will need to arrange transportation to your final destination after you arrive at the airport. To help track airline performance, the U.S. Bureau of Transportation Statistics of the Department of Transportation publishes statistics. For the purposes of this dataset, a flight is considered delayed if it arrived at (or departed from) the gate 15 minutes or more after the scheduled arrival (or departure) time as reflected in the Computerized Reservation System.

We will explore the distribution of monthly percentage of domestic flights delayed in the United States using a sample of data for the years 2010 through 2019 by making a histogram with bins starting at 9% and a bin width of 3%. We will then determine the z-scores for a delayed percentage of (a) 14% and (b) 25%.

The dataset consists of the percentage of flights delayed for each month for years 2010 through 2019 for domestic flights in the United States.

†Airline Performance: Bureau of Transportation Statistics. (2020, September 1). On-Time Performance - Flight Delays at a Glance. United States Department of Transportation. https://www.transtats.bts.gov/HomeDrillChart.asp
Year	Month	Delayed (%)
2010	January	18.58
2010	February	19.66
2010	March	18.3
2010	April	13.83
2010	May	18.55

Import the dataset into SALT for analyzing.

A button hyperlink to the SALT program that reads: Use SALT.

Business

Undergraduate business students at a public university in the midwestern United States ran a café one semester and collected data each business day to help make sound business decisions and to be more profitable. Among other things, the daily total cash register sales were recorded.

We will explore the distribution of daily total sales for this café using a sample of data from one semester by making a histogram of Sales ($) with bins starting at $60 and a bin width of $25. We will then determine the z-scores for a day when total sales were (a) $195 and (b) $90.

The dataset consists of data recorded across one semester including an index number that puts the observations in chronological order, the day of the week, and the total sales in dollars.

†http://jse.amstat.org/jse_data_archive.htm
Index	Day of Week	Sales($)
1	Tuesday	199.95
2	Wednesday	195.74
3	Thursday	102.68
4	Friday	162.88
5	Monday	101.76

Import the dataset into SALT for analyzing.

Sports

It goes without saying that professional basketball players are tall. Height obviously matters when it comes to playing basketball and tall people are more efficient because they can reach the basket easily, allowing for more points per game, as well as more rebounds and blocked shots. If you watch National Basketball Association (NBA) games regularly, you certainly notice that many players are quite tall.

We will explore the distribution of NBA player heights using a sample of players active in the 2019-2020 season by making a histogram of "HEIGHT (INCHES)" with bins stating at 68 inches and a bin width of 2 inches. We will then determine the z-scores for players who are 71 inches (5'11") and (b) 83 inches (6'11").

The dataset consists of the NBA player's name, team, and height, measured in inches, for players active in the 2019-2020 season.

†https://www.nba.com/stats/players/bio/
Player	Team	Height (Inches)
Aaron Gordon	ORL	80
Aaron Holiday	IND	73
Abdel Nader	OKC	77
Adam Mokoka	CHI	77
Admiral Schofield	WAS	77

Import the dataset into SALT for analyzing.

After you have clicked the tab for your selected topic and read the problem, answer the questions below.

(a)

Use SALT to summarize the data and fill in the following table, rounding values to four decimal places as needed.

Variable	N	Mean	Standard Deviation	Median	Minimum Value	Maximum Value
Numerical Variable

(b)

Create a histogram with "Starting Point" and "Bin/Class Width" values asked for.

The distribution for this variable

mound shaped and

at least roughly symmetric.

(c)

Determine the relative standing for the two data values of interest using the z-score formula appropriate for samples. Round your answers to two decimal places.

Data value (a).

z

=

x − x

s

=

Data value (b).

z

=

x − x

s

=

Data value (a) is standard deviations the mean whereas data value (b) is standard deviations the mean. (Remember to take the absolute value of the z-score to determine the number of standard deviations each data value is away from the mean.)

(d)

Most data points are within three standard deviations of the mean. In other words, most observations will have a z-score that is larger than 3 and less than 3.

Find the data value with a z-score of −3, rounded to two decimal places.

x	=	z · s + x

	=

Find the data value with a z-score of 3, rounded to two decimal places.

x	=	z · s + x

	=

Our sample's minimum value further than 3 standard deviations below the mean. Our sample's maximum further than 3 standard deviations above the mean. Upon further inspection of the histogram in SALT it can be observed that observations would have a z-score between −3 and 3.

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3. –/18 points BBUnderStat13 PJT.1.001. My Notes

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This exercise will gain student interest.
Project Milestones allow instructors to assign and track long-term projects that enable students to design and conduct their own statistical research to help solidify big picture understanding.

Milestone 1: Research Design

Question 1

What is your research question?

Your research question should be based on a topic that interests you and that you can reasonably obtain data for. Try to make your research question as specific as possible. Form a research question about a population that you will be able to sample. Some examples of research questions are: "Are students at my college able to taste the difference between regular coffee and decaffeinated coffee?", "Does the GPA, age, and number of credits needed for graduation for juniors at my university differ between transfer students and non-transfer students?", "Have the new water rates in my water district changed residents' water usage habits?", and "Do recent graduates from the business department at my university get larger starting salaries on average if they have participated in a summer internship?"

This answer has not been graded yet.
Question 2

Has any research already been done that might help with your project?

You can search your university's online database to find articles that discuss research that has already been done on your research question. Please make note of any articles or other sources that helped guide your research question and research design. You will be asked to provide references to any sources you used.

This answer has not been graded yet.
Question 3

What is your population of interest?

Your population of interest will be closely related to your research question. For instance, if you are testing the freshman 15 theory and you believe that students at your college do not gain 15 pounds on average over the course of freshman year, then your population of interest is the students at your college who have completed freshman year.

This answer has not been graded yet.
Question 4

Describe your sampling plan.

You want to ensure that your sample is representative of the population of interest. How will you target your population of interest? Sampling involves tradeoffs; you may have to settle for a convenience sample, which is fine for this project as long as you acknowledge this. Sampling is about doing the best you can with the resources you have at your disposal.

This answer has not been graded yet.
Question 5

Will this sample be representative of the population of interest? If so, why? If not, what population will the sample be representative of?

Is there any group of people within the population of interest that your sampling plan is likely to miss? For instance, if you are using a random sample of landline telephone numbers from your state in order to achieve a random sample of residents in your state, then you are missing all of the residents of your state who only have a cell phone and do not have a landline. Or, if your population of interest is all adults in your country, but you only conduct interview of adults from your local community, then your sample is only representative of the adults in your local community.

This answer has not been graded yet.

Question 6

What variables will you measure?

Make sure that the variables you choose are measurable. If you are performing an experiment where you are comparing two skin creams to determine which gives the skin a more youthful glow, how exactly will you measure "youthful glow"? Are there other variables that you will collect because they too may be of interest? Age? Gender? Level of education? Is your variable type numeric or categorical? If your variable type is numeric, is it discrete or continuous? Do your variables need to be measured using special equipment?

Variable	Type	How will you measure it?
		This answer has not been graded yet.
		This answer has not been graded yet.
		This answer has not been graded yet.
		This answer has not been graded yet.

Question 7

Describe your study design.

Will you be conducting an observational study or performing an experiment? What will your sample size be? If you will be performing an experiment, will there be a placebo? If so, describe the placebo. Will the experiment be blinded? Double-blinded? Who will carry out the experiment and how?

This answer has not been graded yet.

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4. –/4 points BBUnderStat13 2.1.013.S. My Notes

5. –/18 points BBUnderStat13 2.1.ST.001.S. My Notes

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This exercise will explore real data with technology.
Statistical Analysis and Learning Tool Tutorial questions help students understand how to use SALT in their WebAssign assignments with step-by-step instructions.

The following exercise will guide you through how to use SALT to make a histogram.

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6. –/9 points BBUnderStat13 2.Lab.001.Excel. My Notes

This exercise will explore real data with technology.
Students perform real statistical analysis in class or online with pre-built, chapter-specific Stats Labs using the data analysis tool of your choice (R, JMP, Minitab, SPSS, Excel or Graphing Calculator) to analyze a real dataset—facilitating whole-picture learning.

Statistical Lab

Background

The National Institutes of Health conducts ongoing surveys of US adults called the Health Information National Trends Survey (hereafter abbreviated HINTS).

From the National Institutes of Health: "The HINTS data collection program was created to monitor changes in the rapidly evolving field of health communication. Survey researchers are using the data to understand how adults 18 years and older use different communication channels, including the Internet, to obtain vital health information for themselves and their loved ones...."

A doctor and a patient are talking in an examination room.

The most recent round of data collection occurred over the course of September 2013–November, 2013 in HINTS 4 Cycle 3. In this lab, you will be using a subset of the HINTS 4 Cycle 3 data to practice creating effective and informative graphical representations of data, which may include histograms and pie charts.
About the Data
For this lab, you need to download the hintsdata.csv dataset. The variables you will be working with are as follows.
- Age—assume each person's age was rounded to the nearest year; for example, a person in the age
  range [19.5, 20.5)
  would have a reported age of 20, and a person in the
  range [20.5, 21.5)
  would have a reported age of 21, and so on.
- Gender—the gender of the respondent; categories include 1 = Male and 2 = Female.
- GeneralHealth—how the respondent rates their overall health; categories include 1 = Excellent, 2 = Very Good, 3 = Good, 4 = Fair, 5 = Poor.
General Notes
A few important aspects of creating effective graphical displays of data include the following.
1. labeling your graphs with descriptive titles
2. ensuring that the x- and y-axes have appropriate labels
3. setting the axes to meaningful and/or useful scales
Your graphs are expected to have these three characteristics.
Tech Guide

You will need to use the Excel Tech Guide.
Lab Questions

Create a histogram of the variable Age with class intervals 10 years wide. (Submit a file with a maximum size of 1 MB.)

This answer has not been graded yet.

Describe the shape of the above histogram.

The distribution is , centered near , with variability.

Create a pie chart of the variable GeneralHealth. (Submit a file with a maximum size of 1 MB.)

This answer has not been graded yet.

Describe how the majority of people in the survey feel about their general state of health.

The majority of people in the survey feel that their general state of health is .

You wish to determine if the age of the respondents who perceive themselves to be in good health differs from the age of the respondents who perceive themselves to be in poor health. Do this by creating two histograms. For the first histogram, plot the variable Age using only the data from respondents who rate their overall health as Excellent, Very Good, or Good. For the second histogram, plot the variable Age using only the data from respondents who rate their overall health as Fair or Poor. Make sure to label your histograms and make sure that they have the same limits for the x-axis, y-axis, and class intervals, so that they can be directly compared. (Submit a file with a maximum size of 1 MB.)

This answer has not been graded yet.

Briefly discuss.

This answer has not been graded yet.

Compare how men and women rate their general state of health using a comparative chart. Using your chart, briefly compare and contrast how men and women rate their general state of health.

This answer has not been graded yet.

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7. –/3 points BBUnderStat13 1.CE.001.CV. My Notes

8. 1/3 points | Previous Answers BBUnderStat13 9.2.012. My Notes

This exercise will improve conceptual understanding.
Personalized Feedback: With the recent upgrade to the latest version of Mathematica, WebAssign will provide even more support to your students through additional question feedback for select questions. This feedback addresses common student mistakes including imprecise answer formatting, improper rounding, inadvertently including or not including a sign, incorrect fraction formatting, improper use of variables or capitalization, missing or incorrect exponents and more.

The following Minitab display gives information regarding the relationship between the body weight of a child (in kilograms) and the metabolic rate of the child (in 100 kcal/ 24 hr).

Predictor	Coef	SE Coef	T	P
Constant	0.8570	0.4148	2.07	0.0843
Weight	0.39539	0.02978	13.28	0.0000

S = 0.517508,
R-Sq = 96.2%

(a)

Write out the least-squares equation. (Let x be the weight of a child in kilograms.)

ŷ =

0.39539y+0.857

Check which variable(s) should be in your answer.

(b)

For each 1 kilogram increase in weight, how much does the metabolic rate of a child increase? (Use 5 decimal places.)

(c)

What is the value of the correlation coefficient r? (Round your answer to three decimal places.)

r =

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9. 0/3 points | Previous Answers BBUnderStat13 7.3.030. My Notes

This exercise will improve conceptual understanding.
Personalized Feedback: With the recent upgrade to the latest version of Mathematica, WebAssign will provide even more support to your students through additional question feedback for select questions. This feedback addresses common student mistakes including imprecise answer formatting, improper rounding, inadvertently including or not including a sign, incorrect fraction formatting, improper use of variables or capitalization, missing or incorrect exponents and more.
Read It links are available as a learning tool under each question so students can quickly jump to the corresponding section of the eTextbook.

Why do we use 1⁄4 in place of p(1 − p) in the formula below for sample size when the probability of success p is unknown?

n =

1

4

z_c

E

	2

if you do not have a preliminary estimate for p

(a)

Show that

p(1 − p) =

1

4

−

p −

1

2

	2

.

1

4

−

p −

1

2

	2

=

1

4

−

p² +

4

=

p +

5

=

p(1 − p)

(b)

Why is p(1 − p) never greater than

1

4

?

The maximum value p(1 − p) can take is when p = 1⁄4, which gives a result of 1⁄4. The maximum value p(1 − p) can take is when p = 1⁄2, which gives a result of 1⁄4. The maximum value p(1 − p) can take is when p = 1⁄4, which gives a result of 1⁄2. The maximum value p(1 − p) can take is when p = 1⁄3, which gives a result of 1⁄4.

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10. –/6 points BBUnderStat13 7.1.020.MI. My Notes

This exercise will improve conceptual understanding.
Students get just-in-time learning support with Watch It videos that contain narrated and closed-captioned videos walking students through the proper steps to solve a similar problem.
Master It tutorials are an optional student-help tool available within select questions for just-in-time support. Students can use the tutorial to guide them through the problem-solving process step-by-step using different numbers.

Allen's hummingbird (Selasphorus sasin) has been studied by zoologist Bill Alther.†Reference: Hummingbirds by K. Long and W. Alther Suppose a small group of 12 Allen's hummingbirds has been under study in Arizona. The average weight for these birds is x = 3.15 grams. Based on previous studies, we can assume that the weights of Allen's hummingbirds have a normal distribution, with σ = 0.28 gram.

(a)

Find an 80% confidence interval for the average weights of Allen's hummingbirds in the study region. What is the margin of error? (Round your answers to two decimal places.)

lower limit upper limit margin of error

(b)

What conditions are necessary for your calculations? (Select all that apply.)

(c)

Interpret your results in the context of this problem.

The probability that this interval contains the true average weight of Allen's hummingbirds is 0.80. We are 80% confident that the true average weight of Allen's hummingbirds falls within this interval. The probability that this interval contains the true average weight of Allen's hummingbirds is 0.20. We are 20% confident that the true average weight of Allen's hummingbirds falls within this interval.

(d)

Find the sample size necessary for an 80% confidence level with a maximal margin of error E = 0.06 for the mean weights of the hummingbirds. (Round up to the nearest whole number.)

hummingbirds

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Brase and Brase - Understandable Statistics 13/e (Homework)

Current Score : 9 / 88

Due : Sunday, January 27, 2030 23:30 EST

Last Saved : n/a Saving... ()

Instructions

Assignment Submission

Assignment Scoring

Stats in Practice

Part I - Multiple Choice Questions

Part II - Discussion Question

Milestone 1: Research Design

Question 1

Question 2

Question 3

Question 4

Question 5

Question 6

Question 7

Statistical Lab

Background

About the Data

General Notes

Tech Guide

Lab Questions

(a)

(b)

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69	69	70	70	70	75	75	75	75	77	82	82	82
88	89	89	91	91	97	98	98	98	280

54	55	55	57	57	59	60	65	65	65	66	68	68
69	69	70	70	70	75	75	75	75	77	82	82	82
88	89	89	91	91	97	98	98	98	280

WebAssign

Welcome, demo@demo

Brase and Brase - Understandable Statistics 13/e (Homework)

Current Score : 9 / 88

Due : Sunday, January 27, 2030 23:30 EST

Last Saved : n/a Saving... ()

Instructions

Assignment Submission

Assignment Scoring

Stats in Practice

Part I - Multiple Choice Questions

Part II - Discussion Question

Milestone 1: Research Design

Question 1

Question 2

Question 3

Question 4

Question 5

Question 6

Question 7

Statistical Lab

Background

About the Data

General Notes

Tech Guide

Lab Questions

(a)

(b)

54	55	55	57	57	59	60	65	65	65	66	68	68
69	69	70	70	70	75	75	75	75	77	82	82	82
88	89	89	91	91	97	98	98	98	280