STAT 201 Exam 2, Spring 2002

Not To @@ Taken Vu Reserve Reading Roo . e Time: 50 minutes Us April 2, 2002 MATH 207, C, TX QuizI Second Semester, 01-02 (10%) 1.Unaware that 35% of the 10,000 voters in his district still support him, a politician decides to estimate his political strength. A sample of 200 voters shows that 42% support him. a. Is the conclusion of the politician that 42% of the voters support him an example of inferential or descriptive statistics? b. What is the population? c. What is the value of the parameter of interest? d. What is the value of the statistic of interest? (10%) 2.A business has 120 employees, each identified with an ID number with 3 digits 001,002,...099,100,...,120 . Explain clearly how you would choose a systematic sample of 10 employees out of the 120 employees. (27%) 3.The following data give the market value (in millions of U.S. dollars) in 1996, of 24 Canadian companies. 13,900 12,918 12,540 11,318 9729 8115 7493 7386 7045 7017 6806 6224 6008 5631 5473 5431 4864 4720 4693 4615 3979 3773 3704 3487 a. Construct a grouped-data table including frequencies, relative frequencies and midpoints. Use classes of equal width starting with the class 3000 < 6000 million. b. Draw a relative frequency histogram for the data. b. What percentage of the companies is worth 9 billion or more? (1 billion = 1000 million) (28%) 4.Following are the temperatures (in degrees Fahrenheit) observed during 8 wintry days in a certain city. 23 «14 6 0 2 9 16 19 a. Find the mean and the range of the data. b. Find the variance and the standard deviation. (Use the computing formula). c. Calculate the z-scores of the temperatures 16 and 2. (25%) 5. The following are the test scores of 12 students in a math class. 75 80 68 53 99 58 76 85 88 91 79 73 a. Find the three quartiles. b. Find the Interquartile Range and interpret it. Ss T met 3) ! fe MATT 209 tevane Reading Room “4 Qui2me Second Semester Ol -9O >". Solutions (GO) La leant: of Heotistras (2 “Me 10,020 voters in the districg. Cy) ZB35°%. (a> 4 AY. a Divide 100 by seme number /O. Ancuser is [Q. “Telee Eicsh 1A numbers in Q:ist: }—»tArA. Llse vrondom Aum leacsPeliogse. One namleer CW aendenty ) From them. Call st MW. Stect wid 1 as dee Cirst Dumleke in. you sompeLe ernk add IR to es dimes. UntsQ ou lave LO AuUmlegcs . Foc ek am if Oc 5» the LO NUM eeec 01 LQ lee: F514 5315 43) SS) 6F, 49 91,103, IIS 3. Chass “Tally Fred Wau cy ; Riek. Frequency IE kpe ab BOPAEGOQO =H NY | {1 Vays 0-H - 4 S90. G200<F080 MLL! & R/ay = 0-33 Seo 4o00 < lQooa im a B/a4 =0-o8 1d,500 12600 <!So00 [11 3 3/ay =0.13 (23,8500. Mee anetene, Mistedeaen: | Ay} a “e Adien Componies Vay ray 4, J 2D Bee GaeD Geen '2ana Gono Moricet Value in millims Wot To Be Taken: x , Reserve Reading Root: vy” @ ly, QA. Ween Kz Sx _ BH 2 NASR llta 8B ~S. Rome = lo. ekest —sma lee =Aa2P-O =93 b, * a3 $a \* ue 146 cao 207 EX & 36 i) o 8608 s. 463 - 7 67.5835 a 4 =) ol 8 | Ss? is) Variance: (6 356 S:D. s=\\vosmn = 2,92 (G Bél ce Stadord Scores! Foc x2/6) ze (6-113 _ 589 8:2 7 Vor & = 2, ve QR H-—NNB_ _he |] ascending Baa S53 58 68!493 #5 46599 So 25,8R 41 99 fay) Qo, a S.Stips 6 Sthpas Sd pos. Qa =tt?F. 975, Qiz GBtF93 270-5; Qa SS+ B8 = BES TQA- Qa — Qe BES -FOS= 1é Late p~etotion : Middle 50% of data values Orewiduin 1G maids. Boxpfot ' Q, 2 = 3 ! 50 S55 Go Fo IR5 ES aq 45 AN RN Bo