Assignment 1
Question 1
Classify each variable in this data table as dichotomous, categorical, ordinal or continuous.
|
Name
|
Sex
|
Age in years
|
County of birth
|
Weight category
|
|
John Snow
|
M
|
45
|
England
|
obese
|
|
William Farr
|
M
|
75
|
New Zealand
|
normal
|
|
Joseph Goldberger
|
M
|
54
|
Spain
|
overweight
|
|
Janet Lane
|
F
|
90
|
New Zealand
|
underweight
|
Question 2
Using the ‘fham.p1.RData' data set introduced in tutorial 3 and R Commander, draw separate histograms ofbody mass index for males and females.
Using the graph alone, describe the centre, spread and shape of distribution of Body Mass Index in females. (Hint: Consider the centre, spread and shape of the histogram. Don't calculate any statistics.)
Using appropriate statistics, describe the distribution of Body Mass Index in males. (Hint: consider measures of centre, spread and shape. Avoid cutting and pasting R commander output - write the answer in your own words.)
Question 3
Using the ‘fham.p1.RData' data set introduced in tutorial 3 and R Commander, graph the relationship between systolic blood pressure (sysbp) and diastolic blood pressure (daibp).(Don't forget to provide meaningful labels on your axes).
Describe in words the relationship between systolic and diastolic blood pressure in this data set.
Question 4
Using the ‘fham.p1.RData' data set introduced in tutorial 3 and R Commander, tabulate the relationship between history of hypertension (hyperten) and history of angina (angina).
If you were to select one person at random from this data set, what is the probability they would have a history of both hypertension and angina?
If you selected person with a history of hypertension at random from this data set what is the probability they would have a history ofangina?
Are history of hypertension and history of angina independent in this data set? Explain why or why not.
Question 5
A telephone survey uses a random digit dialling machine to call subjects. The random digit dialling machine is expected to reach a live person 15% of the time.
In eight attempts what is the probability of two successful calls?
What is the probability of two or fewer successful calls in 8 attempts?
On average, how many of the 8 calls would be successful? Show any working. (Hint: average is another word for mean)
Question 6
Water samples from a particular site demonstrate a mean coliform level of 10 organisms per litre with standard deviation 2. Values vary according to a Normal distribution.
What percentage of samples will contain between 13and 14 coliform organisms? Show any working.
We could expect at least 95% of all samples to contain less than how many coliform organisms?
Question 7
Suppose the distribution of serum cholesterol value sin undergraduate mean is approximately Normal with mean μ = 190 milligrams per decilitre (mg/dl) and standard deviation σ = 40 mg/dl.You take a simple random sample of 49 individuals from this population.
Provide a point estimate of the mean cholesterol in this sample.
Describe the sampling distribution of the sample mean x ¯.
Regarding the mean derived from a sample of n=49, what is the probability of getting a sample mean of less than 180?
Attachment:- Assignment stat.rar