13. What is the correct decision in a hypothesis if the data produce a t-statistic that is in the critical region?

If there is an overall significant F in a one way ANOVA, can we conclude that the group membership or treatment variable caused the observed differences in the group means? Why or Why not?

A study is designed to determine the effect of an office-training course on typing productivity. Fifteen typists who have not taken the course are randomly selected. The investigator assigns 20 pages of equally difficult text to be typed by each typist both before and after completing the training course. The investigator wants to find out whether the training course has reduced the number of errors by more than 10. Define d = Before − After. Significance level  What conclusion should we reach if the p-value is 0.113?

The average American gets a haircut every 43 days. Is the average larger for college students? The data below shows the results of a survey of 11 college students asking them how many days elapse between haircuts. Assume that the distribution of the population is normal. 38, 37, 38, 45, 53, 55, 35, 37, 35, 41, 38 What can be concluded at the the α = 0.05 level of significance level of significance? For this study, we should use? Select an answer: t-test for a population mean?  z-test for a population mean?         The null and alternative hypotheses would be:              H0:H0?   p  or  μ  Select an answer > = ≠ ≤ < ≥                H1:H1?  μ  or p  Select an answer ≠ ≥ > ≤ = <         2. The test statistic ? t z  =  (please show your answer to 3 decimal places.)           The p-value = _______ (Please show your answer to 3 decimal places.)           The p-value is? > or  ≤  α      3.  Based on this, we should?? Select an answer reject ? accept ? or  fail to reject ?…