Student Name Course and Section Number Program of Study STA 2014 Statistics STA 2014 Week 10 Individual Work Assignment Instructions To complete this assignment: 1. 2. Answer all of the questions below in the space provided. Reflect on the information presented in this week's lesson and provide an insightful response to each question. Save and Submit to Dropbox 1. Save your work as a Microsoft Word 2010 (.docx) file that includes your name, course code, and title in the file name. For example: JaneSmith_STA2014_Week10.docx. 2. To submit your assignment, go to the Dropbox and click "Submit Assignment." 3. Click on the drop-down menu to select the Week 10: Individual Work basket in the Dropbox. Objective: Use confidence intervals appropriately. Section 9.1 22. You Explain It! Superstition: A USA Today/Gallup poll asked 1,006 adult Americans how much it would bother them to stay in a room on the 13th oor of a hotel. Interestingly, 13% said it would bother them. The margin of error was 3 percentage points with 95% condence. Which of the following represents a reasonable interpretation of the survey results? For those not reasonable, explain the aw. (a) We are 95% condent that the proportion of adult Americans who would be bothered to stay in a room on the 13th oor is between 0.10 and 0.16. Answer: (b) We are between 92% and 98% condent that 13% of adult Americans would be bothered to stay in a room on the 13th oor. Answer: (c) In 95% of samples of adult Americans, the proportion who would be bothered to stay in a room on the 13th oor is between 0.10 and 0.16. Answer: (d) We are 95% condent that 13% of adult Americans would be bothered to stay in a room on the 13th oor. Answer: Section 9.2 8. (a) Find the t-value such that the area in the right tail is 0.02 with 19 degrees of freedom. Answer: 05/26/2014 Page 1 (b) Find the t-value such that the area in the right tail is 0.10 with 32 degrees of freedom. Answer: (c) Find the t-value such that the area left of the t-value is 0.05 with 6 degrees of freedom. [Hint: Use symmetry.] Answer: (d) Find the critical t-value that corresponds to 95% condence. Assume 16 degrees of freedom. Answer: Section 9.3 7. Aggravated Assault: In a random sample of 40 felons convicted of aggravated assault, it was determined that the mean length of sentencing was 54 months, with a standard deviation of 8 months. Construct and interpret a 95% condence interval for the mean length of sentence for an aggravated assault conviction. Source: Based on data from the U.S. Department of Justice. Answer: 12. Theme Park Spending: In a random sample of 40 visitors to a certain theme park, it was determined that the mean amount of money spent per person at the park (including ticket price) was $93.43 per day with a standard deviation of $15. Construct and interpret a 99% condence interval for the mean amount spent daily per person at the theme park. Answer: 05/26/2014 Page 2 Student Name Course and Section Number Program of Study STA 2014 Statistics STA 2014 Week 12 Individual Work Assignment Instructions To complete this assignment: 1. 2. Answer all of the questions below in the space provided. Reflect on the information presented in this week's lesson and provide an insightful response to each question. Save and Submit to Dropbox 1. Save your work as a Microsoft Word 2010 (.docx) file that includes your name, course code, and title in the file name. For example: JaneSmith_STA2014_Week12.docx. 2. To submit your assignment, go to the Dropbox and click "Submit Assignment." 3. Click on the drop-down menu to select the Week 12: Individual Work basket in the Dropbox. Objective: Test hypotheses regarding a single population parameter. Section 4.1 10. Determine whether the scatter diagram indicates that a linear relation may exist between the two variables. If the relation is linear, determine whether it indicates a positive or negative association between the variables. Answer: 14. Match the linear correlation coefcient to the scatter diagram. The scales on the x- and y-axes are the same for each diagram. (a) r = -0.969 (b) r = -0.049 (c) r = -1 (d) r = -0.992 05/26/2014 Page 1 Answer: 24. The TIMMS Exam Part II (See Problem 23): For the 41 nations that participated in TIMMS, the correlation between the percentage of students who skipped class at least once in the past month and the mean score on the exam was -0.52. Does this suggest there is a linear relation between attendance and achievement score? Write a sentence that explains what this result might mean. Answer: 05/26/2014 Page 2