MGBA - 520 Quiz 4

question (9):   A researcher was interested in the effect of job security on stress. The researcher recruited a random sample of 10 individuals  who had job security and 10 individuals  who were employed on a 1 year contract. The researcher measured the stress hormone through a saliva sample. This is an independent sample design; TRUE OR  FALSE

Question 7

Z=, P-Value=

Question 2 (20 marks) A tutorial school has been running IELTS mock examination for many years. Below is the summary presented by the tutorial school related to the IELTS mock examination in one of the many online classes selected randomly in year 2022. IELTS score in mock examination Number of students < 4 5 2 6 5 7 15 8 10 9 3 A report presented by this tutorial school 5 years ago indicated that the population mean score of IELTS mock examination was 7.05 points and the population proportion of students got 7 points or above was 0.67. (a) Construct a 95% confidence interval estimate of population mean score a student get in the IELTS mock examination in 2022. (b) Test, at 1% level of significance, if the population proportion of students get 7 points or above in 2022 is higher than that in year 2017. (The report must include the (i) null hypothesis and alternative hypothesis, (ii) rejection region(s), (iii) calculation of test statistics, and (iv) conclusion.) (c) If the confidence…

Do people walk faster in the airport when they are departing​ (getting on a​ plane) or do they walk faster when they are arriving​ (getting off a​ plane)? A reputable researcher measured the walking speed of random travelers in two International Airports. His findings are summarized in the table. Complete parts ​(a)-(c) below. ​(a) Is this an observational study or a designed​ experiment? Why?     A. This is an observational study since the researcher influenced the data.   B. This is a designed experiment since the researcher influenced the data.   C. This is an observational study since the researcher did not influence the data.   D. This is a designed experiment since the researcher did not influence the data.   (b)Explain why it is reasonable to use​ Welch's t-test.   A.The samples are​ random, small and independent.   B.The populations are normally distributed.   C.The samples are​ random, large and independent.   (c)The samples are​ random, large and…

How profitable are different sectors of the stock market? One way to answer such a question is to examine profit as a percentage of stockholder equity. A random sample of 32 retail stocks was studied for x1, profit as a percentage of stockholder equity. The result was  x1 = 13.2.  A random sample of 33 utility (gas and electric) stocks was studied for x2, profit as a percentage of stockholder equity. The result was  x2 = 10.0.  Assume ?1 = 4.2 and ?2 = 2.6. Note: For degrees of freedom d.f. not in the Student's t table, use the closest d.f. that is smaller. In some cases, this choice will increase the P-value by a small amount or increase the length of the confidence interval, thereby making the answer slightly more "conservative." (a) Let ?1 represent the population mean profit as a percentage of stockholder equity for retail stocks, and let ?2 represent the population mean profit as a percentage of stockholder equity for utility stocks. Find a 95% confidence interval for ?1 − ?2.…

Question 19 To study whether the students at a university are more or less satisfied with the current food service compared to the previous food service, a sample of 95 current students is taken and finds that 37 are satisfied with the current food service. A similar survey was taken for the previous food service in which 89 students surveyed found that 42 were satisfied with the previous food service. WVhen testing the hypothesis (at the 5% level of significance) a higher percentage of students were satisfied with the previous food service than with the current food service, what is the test statistic? (please round your answer to 2 decimal places)