13. What is the correct decision in a hypothesis if the data produce a t-statistic that is in the critical region? a) Reject H, b) Fail to reject Ho c) Reject H, d) Fail to reject H1

15. In a test of hypothesis about a mean, the critical value for a = 0.05 in a two-tailed test is 1.96. The resulting test statistic value from the sample data is -2.75. Which is the correct decision to make based on the given information? A. Reject the null hypothesis B. Change the alternative hypothesis O C. Fail to reject the null hypothesis D. Redefine the hypothesis

1. For each row of the table you are given a p-value and a level of significance (a). Determine which hypothesis is supported, if the data are significant and which type error could be made. If a given p- value is not a valid p-value (because it is greater than 1), put an x in each box in therow. p-value Hypothesis Họ or H1 Significant or Not Significant Error Type I or Type II 0.043 0.05 0.32 0.05 0.043 0.01 0.0035 0.01 0.043 0.10 0.15 0.10 5.6 x 106 0.05 7.3256 0.01 2. For the hypothesis test, write the concluding sentence in the form used by researchers. Context: Support paying off student dept, H1: p 8 ft, p-value-5.6 x 10°, a=0.05, n=56. 4. For the hypothesis test, write the concluding sentence in the form used by researchers. Context: Blood pressure for men and women, H1: Hw # HM ft, p-value3D0.0035, a=0.01, n=2403.

7. Find the p-value for the following scenarios: a) right-tailed z-test with z=2.3 (12) b) two-tailed z-test with z=2.3 c) left-tailed t-test with r=-2.3 and 16 degrees of freedom d) x* test with X =17.4 with 6 degrees of freedom 517 passengers that flew on planes that did not recirculate air, 98 reported post-flight respiratory symptoms. Out of 583 that flew on planes that did recirculate air, 141 reported post-flight respiratory symptoms. Is there sufficient evidence to support the claim that more passengers had respiratory symptoms that flew with recirculated air? 3. Some airlines recirculate up to 50% of their cabin air in order to increase fuel efficiency. Out of (8)

p = proportion of graduates who get a jobA published article indicates that only 1 in 3 university graduates have a job waiting for them. In an investigation of 200 recent graduates of university A, it was found that 51 had a job. Can it be concluded, with a level of significance of 0.01, that from this university the proportion of graduates who have a job is lower? Choose 1. the correct conclusion2. the correct interpretationSelect one: a) 1. H0 is rejected2. It can be ensured, with 99% confidence, that less than a third of the graduates of said university get a job. b) 1. H0 is not rejected2. It can be ensured, with 99% confidence, that less than a third of the graduates of said university get a job. c) 1. H0 is not rejected2. There is not enough evidence to consider, with 99% confidence, that less than a third of the graduates of said university get a job. d) 1. H0 is rejected2. There is not enough evidence to consider, with 99% confidence, that less than a third of the graduates of…

a) One production process yielded 80 defective pieces in a random sample of size 400 while another yielded 75 defective pieces in a random sample of size 500. Test the Ho: p1 = p2 (that the two processes yield equal proportions of defectives) against the HA: p1 ≠ p2 at 0.05 level of significance. What is the computed value & decision? Select one: a. -1.975, Ho Rejected b. 1.975, Ho Rejected c. -1.975, Ho Accepted d. 1.975, Ho Accepted   b)  Given information below, determine the value of b?             HS Grade:  85     90         85         80         81         87         85         83         87      78    90      82        Col Grade:  2.5    2.0        3.1        3.4        3.9        2.1        2.8        2.9        1.7     2.8   1.4     3.0   Select one: a. -0.1527 b. 0.1527 c. -0.1752 d. -0.1572

5. a). What is a fundamental difference between the t statistic and a z-score in terms of variability? b). What value is estimated with a confidence interval using the t statistic?

3. The producers of a new toothpaste want to see if it is performing similar to their main whitening toothpaste in preventing cavities. Their main whitening tooth paste performance at a six-month checkup is i.73 (o-1.12). To test the new tooth paste, 60 people used it for six-months. At the checkup they found a mean of 1.5 cavities. Perform the appropriate hypothesis testing. Make sure to include all the steps (hypotheses, critical values, calculations, conclusions an interpretations). 0.0 68

1). What is the difference between a t-test for independent samples and a t-test for dependent samples? 2). Provide one study that would be analyzed using a t-Test for dependent samples; then provide one study that would be analyzed using a t-Test for independent samples (Sorry, you can’t use a textbook or lecture example!)

4. In the past, the mean running time for a certain type of cell phone battery has been 19.2 hours. The manufacturer has introduced a change in the production method and wants to perform a hypothesis test to determine whether the mean running time has increased as a result. The hypotheses are: Họ: u=19.2 hours H1: µ>19.2 hours Explain the meaning of a Type I error. A) Concluding that u> 19.2 hours when in fact u = 19.2 hours B) Concluding that u 19.2 hours C) Concluding that u = D) Concluding that u> 19.2 hours when in fact u> 19.2 hours 19.2 hours when in fact u > 19.2 hours