2 The most common hypothesis about the slope is _________ The most common hypothesis about the slope is _________. A regression line with slope 0 is _________. That is, the mean of y (does/does not) change when x changes. So this says that there is no true linear relationship between x and y. Put another way, says there is ___________ between x and y in the population from which we drew our data. You can use the test for zero slope to test the hypothesis of zero correlation between any two quantitative variables.
3 Note that testing correlation makes sense only if the observations are ______.
4 The test statistic is just the standardized version of the least-squares slope b. To test the hypothesis compute the t statistic Once again, we use the t-distribution with n - 2 degrees of freedom and as always our p-value is the area under the tail(s). Regressions output from statistical software usually gives t and its two-sided P-value. For a one-sided test, divide the P-value in the output by 2.
5 Example 15.6: The hypothesis says that crying has no straight-line relationship with IQ. The scatterplot we constructed shows that there is a relationship so it is not surprising that the computer output given on the previous page of notes give t = ______ with a two-sided P-value of _____. There is (strong/weak) evidence that IQ is correlated with crying.
6 Example 15. 7: A previous example (3 Example 15.7: A previous example (3.5) looked at how well the number of beers a student drinks predicts his or her blood alcohol content (BAC). Sixteen student volunteers at Ohio State University drank a randomly assigned number of cans of beer. Thirty minutes later, a police officer measured their BAC. Here are the data.Student:12345678Beers:9BAC:0.100.030.190.120.040.0950.070.06101112131415160.020.050.0850.09
7 Here is the Minitab output for the blood alcohol content data: The regression equation is BAC = Beers S = R-Sq = 80.0% Note: the actual calculated values are slightly different from thesePredictorCoefStDevTPConstant-1.000.332Beers7.480.000
8 Test the hypothesis that the number of beers has no effect on BAC Test the hypothesis that the number of beers has no effect on BAC. Hypotheses: The population of interest is __________________ H0: _______ In words, ____________________________ H1: _______ In words, _________________________________ where is ___________________________