Suppose that someone claims that Australians spend less time on social media than Americans do, and so we want to compare the mean amount of time per day that Americans and Australians spend on social media. Suppose also that a sample of 80 Americans and a sample of 100 Australians are taken, that the sample of Americans spend a mean of 2.3 hrs per day on social media with a standard deviation of 0.8 hrs, and that the sample of Australians spend a mean of 1.9 hrs per day on social media with a standard deviation of 0.6 hrs. If we want to test this claim about the mean time spent by Americans per day on social media - or ??? - and by Australians on social media - or ???? - what would our Hypotheses be in terms of ??? and ????? ? H?: ??? ? ????; H?: ??? > ???? ? H?: ??? = ???? and H?: ??? > ???? ? H?: ??? > ???? and H?: ??? = ???? ? H?: ??? ? ???? and H?: ??? < ???? ? H?: ??? = ???? and H?: ??? ? ???? ? H?: ??? > ????; H?: ??? < ???? In Question 9, what would the degrees of freedom of our test statistic be (before using the t-Table)?
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In this case, we want to test if Australians spend less time on social media than Americans do. Therefore, the null hypothesis (H0) is that the mean time spent on social media by Americans is less than or equal to the mean time spent by Australians. The Show more…
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