Significance test using the t distribution. A test of a null hypothesis versus a two-sided alternative gives t 2.22. (a) The sample size is 18. Is the test result significant at the 5% level? Explain how you obtained your answer. (b) The sample size is 9. Is the test result significant at the 5% level? Explain how you obtained your answer. (c) Sketch the two t distributions to illustrate your answers.

Section 1.1 The Structure of Data Statistics: Unlocking the Power of DatLock Outline ●Data ●Cases and variables ●Categorical and quantitative variables ●Explanatory and response variables ●Using data to answer a question Statistics: Unlocking the Power of DLock Why Statistics ● Statistics is all about DATA ○ Collecting DATA ○ Describing DATA – summarizing, visualizing ○ Analyzing DATA ● Data are everywhere! Regardless of your field, interests, lifestyle, etc., you will almost definitely have to make decisions based on data, or evaluate decisions someone else has made based on data Statistics: Unlocking the Power of Data Lock Data ● Data are a set of measurem