Probability and Statistics for Engineering and the Sciences 8th Edition Chapter 1 Overview and Descriptive Statistics
Page 12 Problem 1 Answer
Given, Statement says that we need to”Give three different examples of concrete populations and three different examples of hypothetical populations.”
Example of concrete populations:
All student who take JAM exam in the year 2021.
All workers at your University.
Number of students participate in recent college quiz competition.
Examples of hypothetical populations:
All possible samples of a particular type of cancer tissue.
Average students at your University participated in scholarship exam in next academic year.
Page length of scientific papers published in 2015.
Hence,some of the example of concrete populations are as follows:
All student who attend JAM exam in the year 2021.
All workers at your University.Strength of students participated in recent college quiz competition.
Similarly,some examples of hypothetical populations are as follows:
All probable samples of a particular type of cancer tissue.
Average students at your University attended scholarship exam for the next academic year.
Page length of scientific papers published in 2015
Page 12 Problem 2 Answer
Given,We need to give an example of a probability question and also an example of an inferential statistics question for each one of your concrete and hypothetical populations.
Probability questions for concrete populations:
What is the probability of getting an Ace? What is the probability of getting at least 1 King? What is the probability of getting 2 heads when three coins are flipped once?
Probability questions for hypothetical populations: What is the probability that you threw a stone more than 100 meters? What is the probability of the drug being more toxic than 15(units)?What is the probability of student going to have average grade bigger than 4.9?
Inferential static question for concrete population: Are the basketball athletes of 2013 more accurate than those of 2003?
Inferential static question for hypothetical population: Can we conclude the average grade of all students average grades will be below 4 the given 5 sampled students at your University have an average grade of 2.3,4.2,4.3,3.9,4 ?
Probability questions for concrete populations:
What is the probability of getting an Ace? What is the probability of getting at least 1 King? What is the probability of getting 2 heads when three coins are flipped once?
Probability questions for hypothetical populations: What is the probability that you threw a stone more than 100 meters? What is the probability of the drug being more toxic than 15 (units)? What is the probability of student going to have average grade bigger than 4.9?
Inferential static question for concrete population:
Are the basketball athletes of 2013 more accurate than those of 2003?
Inferential static question for hypothetical population:
Can we conclude the average grade of all students average grades will be below 4 the given 5 sampled students at your University have an average grade of 2.3,4.2,4.3,3.9,4 ?
Page 12 Problem 3 Answer
Given, We need to find that if scores from the SI group a sample from an existing population.
And If we do find those, what are they?If not, what is the most resemble conceptual population?
No, the score from the SI group a sample from an existing population.
In the SI program of this sort all student taking large static course who participate in this sort.
Therefore,it is clear that the score from the SI group is a sample taken from an existing population.
From the above,SI program of this kind all student enrolling in large static course who participate in this sort.
Page 12 Problem 4 Answer
Given,By randomly dividing the students into two groups rather than leaving an option to each student to choose which group to join.
The advantage of randomly dividing the students into the two groups rather than letting each student choose which group to join is:
It safeguards against various bias.
It helps in ensuring that those who are in SI groups are as similar as possible to the student in the control group.
Therefore,the advantages are observed as: It helps and safeguard against various bias.
It helps in ensuring that those who are in SI groups are as similar as possible to the student in the control group.
Page 12 Problem 5 Answer
Given, Statement in the article says that “Supplemental Instruction: An Effective Component of Student Affairs Programming” (J. of College Student Devel ., 1997: 577−586 ).
Now, The investigators put all students in the treatment group because there is no firm basis for assessing the effectiveness of SI.
The SI scores cannot be reasonably compared with anything.
Therefore,the investigators put all students in the treatment group because of the reason that there is no strong basis for assessing the effectiveness of SI.
These SI scores cannot be compared having proper reason with anything.
Page 12 Problem 6 Answer
Given: A certain city is naturally divided into ten districts.
A real estate appraiser selects a sample of single-family homes that could be used as a basis for developing an equation to predict the estimated value based on characteristics such as age, size, number of bathrooms, distance from the home. next school etc.
When all single family homes in the city is given then we can generate the simple random samples or the stratified random sample.
In stratified random sample we take the simple random sample from each of the district neighborhoods.
Values of all desired variables would be determined from each of the selected homes.
Now, we can conclude that their exists a finite, identifiable population of objects from which to sample.
So, this is the enumerative study.
We can conclude that there is a finite and identifiable population of objects to sample from, so this is the enumerative study.
Page 12 Problem 7 Answer
Given: The flow rate through a solenoid valve in an automobile emission control system is an important characteristic.
An experiment was conducted to investigate how the flow rate depends on three factors: armature length, spring force and coil depth.
Two different levels (low and high). ) of each factor, and a single flow observation was made for each combination of levels.
Total factors are 3.
Each factors receive one of two possible level.
Low level is represented by L.
High level is represented by H.
The total observations are 8 are 8 are given as :
{LLL, LLH, LHL, LHH, HLL, HLH, HHL, HHH}
Hence,the total observations that resulting data set consisted are 8 are given as :
{ LLL, LLH,LHL, LHH,HLL,HLH,HHL,HHH}
Page 12 Problem 8 Answer
The flow rate through a solenoid valve in an automobile emission control system is an important characteristic.
An experiment was conducted to investigate how the flow rate depends on three factors: armature length, spring force and coil depth.
Two different levels (low and high). ) of each factor and a single flow observation was made for each combination of levels.
Enumerative study: This study is identifiable not ambiguous. In this study, the elements of the population are well-defined and unchanging. In this study, a sampling frame which is a list of sample points to be collected is either available to an investigator or else can be constructed.
Analytic study: It is not an enumerative study. It is a process that does not even exit at the time of the study.
The study does not have a well-defined sampling frame and the impact of this study is highly localized and short term.
The given study is analytic study.
Because we are investigating the amount of flow through solenoid valve.
Hence, this can be improved in the future.
Therefore,an experiment was carried out to study how flow rate depended on three factors: armature length, spring load, and bobbin depth.
The given study is analytic study.