SOLUTIONSMAT 167: StatisticsTest IIInstructor: Anthony TanbakuchiFall 2008Name:Computer / Seat Number:No books, notes, or friends.Show your work.You may use the attachedequation sheet, R, and a calculator. No other materials. If you choose to use R,write what you typed on the test or copy and paste your work into a worddocument labeling the question number it corresponds to. When you are donewith the test print out the document. Be sure to save often on a memory stick justin case. Using any other program or having any other documents open on thecomputer will constitute cheating.You have until the end of class to finish the exam, manage your time wisely.If something is unclear quietly come up and ask me.If the question is legitimate I will inform the whole class.Express all final answers to 3 significant digits. Probabilities should be given as adecimal number unless a percent is requested. Circle final answers, ambiguous ormultiple answers will not be accepted. Show steps where appropriate.The exam consists of 18 questions for a total of 70 points on 11 pages.This Exam is being given under the guidelines of our institution’sCode of Academic Ethics. You are expected to respect those guidelines.Points Earned:out of 70 total pointsExam Score:
MAT 167: Statistics, Test IISOLUTIONS p. 1 of 11Solution:Fall 2008 results.>summary( score )Min .1 stQu.MedianMean 3rd Qu.Max.65.7174.2978.9380.2490.1892.86>par (mfrow = c (1 ,2))>boxplot ( score ,main = ”Boxplotofexamscores ”)>h i s t ( score ,main = ”Histogramofexamscores ”)657075808590Boxplot of exam scoresHistogram of exam scoresscoreFrequency65707580859095012341. (1 point) Why is it important to use random sampling?2. For the following statements, determine if the calculation requires the use of apopulationdistributionor asampling distribution.(a) (1 point) Computing a confidence interval for a mean.Solution:Sampling distribution. We need to utilize the distribution of the samplemeans.(b) (1 point) Determining a p-value for a one sample proportion hypothesis test.Solution:Sampling distribution. We need to utilize the distribution of the samplestatistic.(c) (1 point) Calculating the probability than an individual weights more than 100 lbs.Solution:Population distribution. We need to utilize the distribution of individual’sweights (the population).Instructor: Anthony TanbakuchiPoints earned:/ 4 points
MAT 167: Statistics, Test IISOLUTIONS p. 2 of 11(d) (1 point) Computing an interval that contain 95% of individual’s weights.Solution:Population distribution. We need to utilize the distribution of individual’sweights (the population).