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Which one is culturally appropriate behavior to inform someone such as a teacher or boss and others due to absence or tardiness?

Dr. Lofgren was interested in the effects of test anxiety on concentration abilities. Using an anxiety questionnaire, he measured student anxiety levels when the students arrived at his laboratory and then again immediately before taking an examination. Dr. Lofgren hypothesized that participants in his study would have higher anxiety scores immediately prior to the completion of the exam compared to when they first came in. As hypothesized, Dr. Lofgren found that participants’ anxiety scores were significantly higher immediately prior to the examination compared to baseline scores. As a result of this information, what type of t test was Dr. Lofgren MOST likely to use to test his hypothesis? Is Dr. Lofgren’s hypothesis test one-tailed or two-tailed? Explain your answers.

If two sample means come from the exact same distribution, then the distribution of differences between means against which they will be compared should have a mean of:

Marcus is testing to see if men and women send the same number of text messages over the course of a day. He recruits 16 men and 31 women to be in his study. He finds that men send fewer text messages (M = 75, SD = 10) than women (M = 88, SD = 8). When Marcus conducts his t test, what is the pooled variance for this study?

Assume the following for a paired-samples t test: N = 16, Mdifference = 15.19, s = 23.2. What is the t statistic?

Dietz and Henrich (2014) were interested in the impact of texting on student learning. A group of 99 college students were randomly assigned to text (N = 50) or not text (N = 49) during a prerecorded psychology lecture. At the end of the 20-minute lecture, students answered a 17-question quiz about the material that had just been presented. Which statistical test should the researchers use to analyze their data?

Twenty-five college students experience the effects of alcohol on reaction time. They perform very basic timed responses in a driving simulator both before and after consuming several alcoholic beverages. The researcher collects a reaction time result for each of the 25 students before and after intoxication, for a total of 50 measures. What are the degrees of freedom for this study?

As N increases, the width of the confidence interval increases.

Why do we divide by N – 1 rather than by N when estimating a population standard deviation from the sample standard deviation?

The minimum acceptable level of estimated power for a study is: