uppose a researcher is interested in evaluating the effectiveness of a new teaching method on reading comprehension. So, she randomly selects one classroom from the neighborhood school. She first administers a reading comprehension test to a group of twenty-five students and obtains a mean reading score of 135 (s = 10). She then implements the new teaching method. At the end of 10 weeks, she administers a reading comprehension test to the students again and obtains a mean score of 160 (s = 5). (1) State the null and alternative hypotheses for this study (2) What is the dependent and independent variable for this study (3) What test statistic/hypothesis test would you select to determine if the means are significantly difference at the alpha .05 level? (4) What critical value would you use to make your decision to reject or retain the null hypothesis at alpha .05?

What was the power for this study?

An important measure in the study of contagious infectious diseases is the number of cases directly generated by one previous case. Jessica is an epidemiologist studying the spread of an infectious disease in her country. She claimed that the mean number of cases directly generated by one previous case is now greater than 1.2. A study of 12 randomly selected cases of the disease is conducted and finds the sample mean number of cases directly generated by one previous case to be 1.5 with a sample standard deviation of 0.7. Assume that the population of the number of cases directly generated by one previous case is approximately normally distributed. Complete the parts below to perform a hypothesis test to see if there is enough evidence, at the 0.10 level of significance, to support the claim that u, the mean number of cases directly generated by one previous case, is greater than 1.2. (a) State the null hypothesis H, and the alternative hypothesis H, that you would use for the test.…

A researcher gathered a sample of participants who volunteered for a studying of phobias. She measured anxiety level of participants as they viewed photos of spiders and again when they viewed puppies. Which statistical test is appropriate for this study and why?