Who spend more time on the daily commute Sydney siders or Melbournians

# Who spend more time on the daily commute sydney

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– Who spend more time on the daily commute, Sydney- siders or Melbournians? – Statement you regular encounter in the media: such as “Men earn more money than women”; or “Smoking shortens smokers’ lives by about 12 years” 11 Sample characteristics vs. population characteristics Sample characteristics – what you calculate from the sample, e.g., average satisfaction for HP computer among male respondents is 1.51 Population characteristics The “true” values (e.g., “true” satisfaction for HP computer among male customers What your RQs are about Unfortunately, the values are unknown (and unknowable in this case) In its essence, the hypothesis testing process is to use observable relationships between sample characteristics to make inference about relationships between the unknown population characteristics 12
MKF2121 5 Variability Sample characteristics are random variables, e.g., if you collect data for a few times—e.g., with different samples, or at different times—you will get different sample averages This variability is an issue that needs to be accounted for with statistical analysis (in another word, is the difference in satisfaction we observe in the sample between men and women real, or just noise?) The first step is to quantity the variability in sample characteristics in your data (e.g., through metrics such as variance and standard deviation) 13 How do you really “answer” a research question? The ritualistic dance of hypothesis testing 1. Problem Definition 2. Clearly State the Null and Alternative Hypotheses 3. Choose the relevant statistical test 4. Calculate p-value 5. Is p-value<0.05? No Do not reject null Reject null hypothesis Yes 14 1. Problem definition 4/6/2017 15 You have done this already, i.e., your research question Do men and women differ in their satisfaction with HP computer?