Progress CheckUse this activity to assess whether you and your peers can: Calculate a 90% and a 95% confidence interval.Relate the interval width of a confidence interval to its margin of error (MOE).Compare interval widths of two confidence intervals and draw conclusions.Learn by DoingUse the rubric at the bottom of this page as a guide for completing this assignment.DirectionsSubmit your work:Commit a good-faith effort to address all items in the Prompt section below. Please be sure to number your responses.Complete your assigned peer reviews:After you submit your initial good-faith attempt, continue to the ANSWER(S) page and review your instructor's response. But please do not submit your corrected work yet.Within three days after the due date, return to this assignment and complete your assigned peer reviews (directions (Links to an external site.)).Submit your corrected work:We all learn from mistakes (our own and our classmates' mistakes). So please do not immediately correct your own mistakes. If possible, wait until you receive feedback from at least one of your peers. If necessary, correct your work and resubmit the entire assignment. Your instructor will only review and grade your most recent submission, so please do not refer to a previous submission.PromptHarris Interactive® conducted a poll of American adults in August of 2011 to study the use of online medical information. Of the 1,019 randomly chosen adults, 60% had used the Internet within the past month to obtain medical information. Use the results of this survey to create an approximate 95% confidence interval estimate for the percentage of all American adults who have used the Internet to obtain medical information in the past month.Calculate the 90% confidence interval.Which confidence interval has the smaller margin of error? Why does this make sense? Which confidence interval is more likely to contain the true percentage of all American adults who have used the Internet to obtain medical information in the past month? Why do you think so?RubricPeer Reviewed AssignmentPeer Reviewed AssignmentCriteriaRatingsPtsThis criterion is linked to a Learning OutcomeAddressing the Prompt8 ptsFull MarksAll parts of the Prompt are addressed. Answers are correct. Statistical vocabulary is used appropriately. Writing is clear and thought process is easy to follow.5 ptsPartial CreditSome parts of the prompt are not addressed, are incorrect, or are unclear.0 ptsNo MarksThe prompt is not addressed.8 ptsThis criterion is linked to a Learning OutcomeIndividual Penalty0 ptsNo individual penalty-1 ptsIndividual penalty.Please see the instructor comments for more information.0 ptsThis criterion is linked to a Learning OutcomePeer Reviews2 ptsFull MarksYou completed all assigned peer reviews (maximum of 2). For each peer review, the points you assigned in the rubric are appropriate. You included comments explaining the score you posted in the rubric. If you deducted points in the rubric, your comments explain what the author needs to do to earn a higher grade when the teacher grades the assignment.1 ptsPartial CreditCommitted a good-faith effort to provide a high-quality peer review, but many necessary instructive comments are missing.0 ptsNo MarksNo peer review provided or the comments are not instructive.2 ptsTotal Points: 10PreviousNext

Learn by DoingSome features of this activity may not work well on a cell phone or tablet. We highly recommend that you complete this activity on a computer.Here are the directions, grading rubric, and definition of high-quality feedback for the Learn by Doing discussion board exercises. A list of StatCrunch directions is provided at the bottom of this page.Variables Math: Math SAT score Verbal: Verbal SAT score Credits: Number of credits the student is registered for Year: Year in college (1=Freshman, 2=Sophomore, 3=Junior, 4=Senior) Exercise: Time (in minutes) spent exercising in a typical day Sleep: Time (in hours) spent sleeping in a typical day Veg: Are you a vegetarian (yes, no, some) Cell: Do you own a smart phone (yes, no)DataIf you have not done so already, download the cell-phones datafile. As always, if you are prompted to login, just close the prompt and continue with the download.Upload the datafile into StatCrunch. Note: the symbol * in the spreadsheet indicates a missing value; this means that the associated individual did not answer the question.ContextIn 2015 college students at a large state university completed a survey about their academic and personal life. Questions ranged from "How many credits are you registered for this semester?" to "Would you define yourself as a vegetarian?"The researcher randomly selected 325 students from the university; 312 responded to the survey.PromptThe cell-phone datafile is available in the Data section below.Once again, here is the research question for this lab.Based on a recent study, roughly 80% of college students in the U.S. own a smartphone. Is the proportion of smartphone owners lower at this university?Respond to each of the following in your initial post.State your hypotheses in symbolic form and in words. (The following should be clear in your answer: the population of interest and the meaning of the proportion p in terms of the variable Cell.)StatCrunch uses a normal model to estimate the P-value probability. Verify that normality conditions are met. Use StatCrunch to conduct the hypothesis test. (directions) Copy and paste the results (the StatCrunch output window) into your initial post.Give your P-value and interpret its meaning as a conditional probability.State a conclusion that answers the research question. Use a significance level of 5%. (Your answer should include the P-value and reference the population and the variable Cell.)