Blackboard 7:48 AM Sun Jun 30 . . . 72% C UST 404 Cha...7 Homework Home Insert Draw Layout Review View References ... Calibri Regular (Bo 14 B I U aAv Ev Eq v is that the mean cost of textbooks it carries is $52 with a standard . The university bookstore claims that the mean cost of texto deviation of $9.50. A group of students want to test this claim. randomly select 36 textbook and find that the mean cost for their sample is $55.80. Assuming a = .05, is the sample mean cost significantly different from it bass in Silver Lake have an average length of 12.3 inches with a standard deviation of 4 inches and a standard error of .3 inches. People who fish often in Silver Lake claim that this year they are catching smaller than usual adult bass. A research group took a random sample of 100 adult bass from Silver Lake and found the mean of this sample to be 11.2 inches. Can the researchers conclude that the fish are smaller than what is normal? Assume a = .01 3. A Type ll error is made when A. we fail to reject the null hypothesis and the null hypothesis is false. e reject the null bootbesis and the humanhypothesis is try D . we reject the null breethesig and the null hypothesis is true . 4. A Type I error is made when A. we fail to reject the null hypothesis and the null hypothesis is false. B. we fail to reject the null hypothesis and the null hypothesis is true. C. we reject the null braethesis and the null hypothesis is false. D. we reject the null hypothesis and the null hypothesis is true 5. A researcher is testing a hypothesis of a single mean. The critical z value for a = .05 and a two-tailed test is $1.96. The calculated test statistic er based on this informatic A. reject the null hypothesis B. fail to reject the null hypothesis C. redefine the null hypothesis D. change the alternate hypothesis . A pharmaceutical company claims that its weight loss drug allows women to lose on average 8.51b after one month of treatment. If we want to conduct an experiment to determine if the patients are ng less weight than advertised, which of the following hypotheses should be used? A. Ho: H S8.5; H,: H > 8.5 B. Ho: M = 8.5; H,: H 8.5 Practice Problems Bowen, Straightforward Statistics 7. A school counselor randomly selects a sample of 30 students to investigate the impact of a behavior QWERTYUIOP their academic performance. If she increases her sample size to 50 she will_ the statistical power of her study. A. increase B. decrease . not impact 8. In general, increasing the alpha level (for example from .01 to .05) will A S D F G H J K L A. increase the likelihoo rejecting the null h lihood of rejecting the null hypothesis C. not affect the likelihood of rejecting the d of rejecting the null hypothesis 9. A newspaper article claims that the average age for people who receive food stamps is 40 years. You e that the average age is less than that. You take a random sample of 100 people who receive Z X C V B N M X food stamps, and find their average age to be 39.2 years. You find that the calculated test statistic within the rejection zone (assuming a = .05). What would be an appropriate interpretation of A. The statistically significant result indicates that the average age of people who receive food stamps is younger than 40. The evidence is not strong enough to support the claim that the average age of people who receive food stamps is younger than 40. 123 space return C. An error must have been made. This difference is too small to be statistically significant 10. A directional hypothesis is known as a_ _ tailed test. Co B IUIO