Biostatistics Assignment 2 - University of Eastern Sydney

Running head: 401077 INTRODUCTION TO BIOSTATISTICS, AUTUMN 2018
401077 Introduction to Biostatistics, Autumn 2018
Assignment 2
Due Sunday April 29, 2018
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401077 INTRODUCTION TO BIOSTATISTICS, AUTUMN 2018
Question 1
The research question being considered is that whether the given data shows evidence
of there being any change in drinking habits from the population in University of Eastern
Sydney. Let p denote the proportion of “more” or “+”. “No change” is equivalent to
proportion of “more” or “+” being equal to proportion of “less” or “-”. Thus the hypotheses
to be tested could be defined as follows:
H0: p =0.5 (Null hypothesis)
H1: p ≠ 0.5 (Alternate hypothesis)
Using sign test, the statistic of interest is X where it represents the number of “+” or
more and follows Binomial (10, p) .The test is thus reduced to test for binomial proportion.
The p-value is used for the decision making at 0.05 level of significance. The p-value was
observed to be 0.3438 which is greater than 0.05. Thus there is not enough evidence to reject
null and claim that drinking habits of the sample has changed from the one at University of
Eastern Sydney.

401077 INTRODUCTION TO BIOSTATISTICS, AUTUMN 2018
Question 2
a.
The 95% confidence interval for the WEMWBS value was found to be (43.73318,
44.42872).
b.
The point estimate of mean well-being score for the student was found to be 44.081.
Additionally, it can be said with 95% confidence that the interval (43.733, 44.429) would
contain the mean value of WEMWBS.
Question 3
a.
The given research question, that whether drug users in University of Eastern Sydney
has lower WEMWBS than non-users, focuses on the case that where WEMWBS score is less