SOLUTIONSMAT 167: StatisticsTest IIInstructor: Anthony TanbakuchiSpring 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 13 questions for a total of 84 points on 12 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 84 total pointsExam Score:
MAT 167: Statistics, Test IISOLUTIONS p. 1 of 12Solution:Spring 2008 results. I made the exam out of 82 points instead of 84.>summary( score )Min .1 stQu.MedianMean 3rd Qu.Max.43.2968.6081.1075.7589.7995.12>par (mfrow = c (1 ,2))>boxplot ( score ,main = ”Boxplotofexamscores ”)>h i s t ( score ,main = ”Histogramofexamscores ”)5060708090Boxplot of exam scoresHistogram of exam scoresscoreFrequency40506070809001234561. An experiment consists of randomly sampling 10 students at Pima Community College, record-ing their heights and computing their mean height. If we repeat the experiment over and over(assume simple random samples, no human errors, no bias) we observe that the sample meanheight varies each time.(a) (2 points) What is the name of the error that causes the mean to vary each time?