MAT 1272 OL 80 Exam 4 Spring 2021 – Morrison May 6, XXXXXXXXXXPM - May 7, XXXXXXXXXX:45 PM Name: _________________________ XXXXXXXXXXEMPLID: ___________________ Each of the 25 questions is 4 points....

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MAT 1272 OL 80 Exam 4 Spring 2021 – Morrison May 6, 2021 1 PM - May 7, 2021 11:45 PM Name: _________________________ EMPLID: ___________________ Each of the 25 questions is 4 points. This section contains questions about statistics vocabulary and concepts. 1. The tails of a normal distribution curve: A) meet the horizontal axis at z = 3.0 B) are not symmetrical C) cross the horizontal axis at z = 4.0 D) never meet or cross the horizontal axis 2. The null hypothesis is a claim about a: A) parameter, where the claim is assumed to be false until it is declared true B) parameter, where the claim is assumed to be true until it is declared false 3. A researcher wants to test if the mean price of houses in an area is greater than 175,000. The null hypothesis for this example will be that the population mean is: A) less than or equal to $175,000 B) greater than or equal to $175,000 C) greater than $175,000 D) not equal to $175,000 4. The sampling error is: A) an error that occurs during collection, recording, and tabulation of data B) an error that occurs when a sample of fewer than 30 members is drawn C) the difference between the value of a sample statistic and the value of the corresponding population parameter D) an error that occurs when a sample of 30 or more members is drawn 5. When samples are selected from a normally distributed population, the sampling distribution of the sample mean has a normal distribution A. if n ≥ 30 B. if ? ? ≤ .05 C. all the time 6. The z-score (rounded to the nearest hundredth) that has 2 .8% to the right is: A) -0.55 B) 0.55 C) -1.91 D) 1.91 7. If the population from which samples are drawn is not normally distributed, then the sampling distribution of the sample mean is: A) never normally distributed B) approximately normally distributed if n is 30 or larger C) always normally distributed D) approximately normally distributed if n is less than 30 8. The mean of the sampling distribution from a population is equal to the population's: A) mean B) mean divided by n C) mean divided by the square root of n D) standard deviation The following information is to be used to answer questions 9 -10: The mean score of all students taking a standardized IQ test is 100 and the standard deviation is 18. If random samples of 40 students are selected from this group: 9. The mean of the sampling distribution will be: A) greater than 100 B) less than 100 C) equal to 100 D) cannot be determined from the given information 10. The standard deviation of the sampling distribution will be: A) greater than 18 B) less than 18 C) equal to 18 D) cannot be determined from the given information 11. If the critical z0 = -1.45 and the sample test statistic is -1.23 would you: A) Reject the Null Hypothesis B) Fail to Reject the Null Hypothesis This section contains questions about statistics calculations. When using the calculator – state all keys pressed and all data entered. Do Not just write the answer. No credit will be given for just an answer even if it is CORRECT. The following information is to be used to answer questions 12 through 15. Binomial Problem: Fifty-seven percent of all adults are in favor of abolishing the sales tax and increasing the income tax. A random sample of 400 adults is selected and asked their opinion on the issue. What is the probability that 216 or fewer will be in favor of abolishing the sales tax? 12. n = 13. p = 14. q = 15. Calculate the requested probability. The following information is to be used to answer questions 16 through 18. The weights of all babies born at a hospital have a mean of 7.3 pounds and a standard deviation of 0.72 pounds. Find the probability that for 36 babies born in this hospital their weights will be between 7.0 and 7.4 pounds. 16. Calculate the z score when weight is 7.0 pounds. 17. Calculate the z score when weight is 7.4 pounds. 18. Calculate the requested probability. 19. The mean Mathematics placement scores for all students in XYZ College are normally distributed with a mean of 21.0 and a standard deviation of 5.3. Students whose scores are in the top 5% are placed into advanced statistics. What is the lowest placement score needed to be placed in this advanced course? The following information is to be used to answer questions 20 through 25. A fast food restaurant claims that the mean sodium content in all its breakfast sandwiches is less than or equal to 920 milligrams with a standard deviation of 18 milligrams. A sample of 44 breakfast sandwiches was taken and the mean sodium content of the sample was 925 milligrams. Test this claim at the alpha = 0.10 significance level. 20. State both the Null and Alternative Hypotheses. 21. Indicate the rejection region on a standard normal curve. 22. Sketch the value of the critical z0 on the standard normal curve. 23. What are the mean and standard deviation of the sampling distribution? 24. What is the z-score of the test statistic? 25. Should the Null Hypothesis be rejected? Make your decision and explain why or why not in at least one sentence.