Ask Question, Ask an Expert

+1-415-315-9853

info@mywordsolution.com

Ask Statistics and Probability Expert

Please follow these instructions carefully, read them first! Your answers should be well structured and concise, and written in complete English sentences. Include your graphs and your code (in typepreparer font), comment it. Do not forget to number your answers to refer to the corresponding tasks below.

Tasks

problem1)

Create a data frame in R that will look like this:

fact variable1
A .
A .
. .
B .
B .
. .
C .
. .
D .
. .
The final dimension of the data set should be 48 rows by 2 columns. Each factor level (A, B, C, D) is replicated 12 times. For variable 1, use the following code:
                          variable1=rnorm(48,10)*(rep(rpois(4,.2),each=12)/8+1)
Give this data frame a name of your choice and show the code you used to create it. describe as much of the code to populate variable 1 with numbers. Comment on the details of the code.

problem 2)

Think of a situation (an experiment or observational study) within your (future) area of research that could produce such a data set. describe (hypothetically) what was done and how the data were obtained. Throughout the rest of this assignment, pretend these are real data. However, in your interpretation, you may comment at any stage on how the data were created.

problem 3)

Explore your data set using at least 2 commands to summarise your data and at least 2 commands to visually depict your data (plots, histograms,...). At each step / for each plot you create, comment on what you see and what you learn from it.

problem 4)

Compare the maximum and minimum values within each group (factor level) to their respective group means. What is the largest absolute difference between one of your values and its group mean? What are the chances of obtaining such a value, assuming the data are normally distributed and centered around the respective group mean with a standard deviation of 1?

problem 5)
 Formulate a hypothesis based on task 1 that you can test using ANOVA. Perform the analysis. Briefly describe what the F-value tells you and interpret the p-value. Draw a conclusion.

problem 6)

Regardless of whether you found significant differences between groups or not, perform a Tukey’s HSD test to determine what groups are significantly different from each other (even if none are). Briefly interpret this result in view of the nature of your data.

problem 7)

describe why the output contains an ‘adjusted p-value’. What does it adjust for? Can you outline a simulation experiment in R (you don’t need but you can show how you would program it) that illustrates the problem of multiple comparisons?

problem 8)

Compute the group means and then the variance of the group means for variable1 and assign this number to an object called ‘betweenVar’, meaning ‘between group variance’. Also compute the within-group variance of variable1 and assign this number to an object called ‘withinVar’ for ‘within group variance’.

problem 9)

Using the within- and between groups variances from the task above, conduct a power test for your ANOVA. Regardless of whether your ANOVA result was significant or not, discuss all aspects of the power test (sample size, type I and type II error, power, within- and between group variance) in accordance with the outcome of your ANOVA (as in task 4) and the nature of your data as you described it in task 1. For ex, if your ANOVA did not find a significant difference between groups, discuss how you could change your experimental set-up to find an expected difference. Or, if your ANOVA was significant, discuss the power of your test and (for ex) your type I error probability and whether / how you could reduce it. Talk about what the design of a larger experiment could look like based on the results of your pilot study, e.g. by bringing in financial aspects.

problem 10)

Show the differences between groups in a bar plot with standard errors. Mark those groups that do not differ significantly with the same letters. Adjust the margins, the label and tick size and position etc. until you think this graph could be published in a journal. Draft a figure caption that contains all the needed information: What is shown? Where? How was it measured? When? What test are the letters referring to?

Statistics and Probability, Statistics

  • Category:- Statistics and Probability
  • Reference No.:- M9427

Have any Question? 


Related Questions in Statistics and Probability

1 what is an interaction2 how many interactions can be

1. What is an interaction? 2. How many interactions can be tested in a 2 x 2 design? In a 3 x 3 design? In a 2 x 2 x 3 design? 3. Why do researchers use expericorr designs?

1 distinguish between theory model and hypothesis2 describe

1. Distinguish between theory, model, and hypothesis. 2. Describe how researchers use induction versus deduction to generate research hypotheses. 3. Describe the process by which hypotheses are developed and tested.

While this campaign ended with a massive us military

While this campaign ended with a massive US military victory in which the Viet Cong were utterly destroyed as a fighting force, it is widely considered a major political defeat for the US because it initiated a major gro ...

A system has two components that operate in parallel at

A system has two components that operate in parallel. At least one of the components must function properly if the system is to function properly. The probabilities of failures for the components 1 and 2 during one perio ...

On a 2-d regular not wrapped-around mesh a message from a

On a 2-D regular (not wrapped-around) mesh, a message from a source (X s , Y s ) is to be sent to a destination (X d , Y d ). If any shortest path can be used, what is the probability that the message follows the shortes ...

Consider the following four-person game in coalitional form

Consider the following four-person game in coalitional form, with transferable utility v({i}) = 0,  ∀i ∈ {1,2,3,4}, v({1,2}) = v({1,3}) = v({2,4}) = v({3,4}) = 1, v({1,4}) = v({2,3}) = 0, v({2,3,4}) = v({1,3,4}) = v({1,2 ...

Consider rolling a fair 6-faced die twice let a be the

Consider rolling a fair 6-faced die twice. Let A be the event that the sum of the two rolls is atmost 6, and B be the event that the first one is an even number. (a) What is the probability that the sum of the two rolls ...

Problem 1 three times each day a quality engineer samples a

Problem 1: Three times each day, a quality engineer samples a component from a recently manufactured batch and tests it. Each part is classified as conforming (suitable for its intended use), downgraded (unsuitable for t ...

1 in an experiment with two independent variables an anova

1. In an experiment with two independent variables, an ANOVA partitions the total variance into four components. What are they? 2. MS wg  appears in the denominator of every F-test. Why?

How does the competitive success of ords kangaroo rat

How does the competitive success of Ord's kangaroo rat change in the absence of coyotes? Propose one possible cause for the decline in rodent diversity in the control areas after treatment begins. What is the impact of c ...

  • 4,153,160 Questions Asked
  • 13,132 Experts
  • 2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

Section onea in an atwood machine suppose two objects of

SECTION ONE (a) In an Atwood Machine, suppose two objects of unequal mass are hung vertically over a frictionless

Part 1you work in hr for a company that operates a factory

Part 1: You work in HR for a company that operates a factory manufacturing fiberglass. There are several hundred empl

Details on advanced accounting paperthis paper is intended

DETAILS ON ADVANCED ACCOUNTING PAPER This paper is intended for students to apply the theoretical knowledge around ac

Create a provider database and related reports and queries

Create a provider database and related reports and queries to capture contact information for potential PC component pro

Describe what you learned about the impact of economic

Describe what you learned about the impact of economic, social, and demographic trends affecting the US labor environmen