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In: Statistics and Probability

1. Many alpine skiers and snowboarders do not use helmets. Do helmets reduce the risk of...

1. Many alpine skiers and snowboarders do not use helmets. Do helmets reduce the risk of head injuries? A study in Norway compared skiers and snowboarders who suffered head injuries with a control group who were not injured. Of 578 subjects with a head injury 96 had worn a helmet. Of the sampled 2992 skiers and snowboarders who had not had a head injury, 656 of them wore helmets. We will compute a confidence interval for the difference in the proportion of skiers and snowboarders who wear helmets between the two groups (no head injury vs head injury). Is helmet use more or less common among skiers and snowboarders who have head injuries?

A) Give the symbols for and define the parameters of interest.

B) Find the observed sample proportions and the observed difference in proportions.

C) Check the conditions to verify the assumptions necessary for a two-proportion confidence interval.

D) Find a 2-proportion 95% confidence interval.

E) Interpret the confidence interval in the context of the problem.6. Does this interval give evidence that helmet use is more or less common among skiers and snowboarders who have head injuries? Explain.

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orchestra answered 2 years ago
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