Hi there, I have put up the full sheet but it is question twothat I need answered the most. Thank you for your time.
Question 1.
Drunk driving is one of the main causes of car accidents.Interviews with drunk drivers who were involved in accidents andsurvived revealed that one of the main problems is that drivers donot realise that they are impaired, thinking “I only had 1-2 drinks… I am OK to drive.” A sample of 5 drivers was chosen, and theirreaction times (seconds) in an obstacle course were measured beforeand after drinking two beers. The purpose of this study was tocheck whether drivers are impaired after drinking two beers. Belowis the data gathered from this study:
Driver 1 2 3 4 5
Before 6.15 2.86 4.55 3.94 4.19
After 6.85 4.78 5.57 4.01 5.72
1. The two measurements are dependent. Explain why. [1 mark]
2. Provide an estimate of the mean difference in reaction timesbetween the two measurements. [4 marks]
3. Calculate and interpret a 95% confidence interval for themean difference in reaction times between the two measurements. [15marks]
4. Use a 5% level of significance and the following points totest the claim that reaction times before drinking two bears islower than reaction times after drinking two bears.
(a) State the null and alternative hypotheses in symbolic formand in context.
(b) Calculate the test statistic.
(c) Identify the rejection region(s).
(d) Clearly state your conclusions (in context). [4 markseach]
5. What would the conclusion be if using a 1% level ofsignificance? Justify your answer. [4 marks]
Question 2
This is part 2, this is the part that I need answered. Thank youfor your time.
It was believed from the experiment on the obstacle course, inPart I, that there is a relationship between a subject’s reactiontime before drinking two beers and the subject’s age:
Driver 1 2 3 4 5
Age (years) 20 30 25 27 26
1. What type of study is being outlined here? Justify youranswer. [2 marks]
2. Plot a graph representing the relationship between reactiontimes before drinking two beers and age. [5 marks]
3. From the graph in Q2, suggest a relationship that could existbetween the two measurements. [2 marks]
4. Use a 1% level of significance and the following points totest the claim that there is a relationship between the reactiontimes before drinking two beers and age.
(a) State the null and alternative hypotheses in context. [3marks]
(b) Calculate the test statistic. [8 marks]
(c) Identify the rejection region(s). [4 marks]
(d) Clearly state your conclusions (in context). [4 marks]
5. What percentage of variation in reaction times beforedrinking two beers is unexplained by the relationship betweenreaction times before drinking two beers and age? [2 marks]
6. Derive a model/equation that could be used to predictreaction times before drinking two beers for a person, if the ageof the person is known. [8 marks]
7. Using the model derived in Q6, what would the predictedreaction time, in the obstacle course, before drinking two beers ofa 22-year-old be? [2 marks
