1. a. Houston Chronicle, Des Moines Register, Chicago Tribune, Washington Post

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1 Homework Soluto. Houto Chrocle, De Moe Regter, Chcago Trbue, Wahgto Pot b. Captal Oe, Campbell Soup, Merrll Lych, Pultzer c. Bll Japer, Kay Reke, Hele Ford, Davd Meedez d..78,.44, 3.5, No, the relevat coceptual populato all core of all tudet who partcpate the SI cojucto wth th partcular tattc coure. b. The advatage to radomly choog tudet to partcpate the two group that we are more lkely to get a ample repreetatve of the populato at large. If t were left to tudet to chooe, there may be a dvo of ablte the two group whch could uecearly affect the outcome of the epermet. c. If all tudet were put the treatmet group there would be o reult wth whch to compare the treatmet tem: oe 0 7 leaf: teth 368 What cottute large or mall varato uually deped o the applcato at had, but a ofte-ued rule of thumb : the varato ted to be large wheever the pread of the data (the dfferece betwee the larget ad mallet obervato) large compared to a repreetatve value. Here, 'large' mea that the percetage cloer to 00% tha t to 0%. For th data, the pread - 5 6, whch cottute 6/8.75, or, 75%, of the typcal data value of 8. Mot reearcher would call th a large amout of varato. b. The data dplay ot perfectly ymmetrc aroud ome mddle/repreetatve value. There ted to be ome potve kewe th dat c. I Chapter, outler are data pot that appear to be very dfferet from the pack. Lookg at the tem-ad-leaf dplay part (a), there appear to be o outler th dat (Chapter gve a more prece defto of what cottute a outler). d. From the tem-ad-leaf dplay part (a), there are 4 value greater tha 0. Therefore, the proporto of data value that eceed 0 4/7.48, or, about 5%.

2 . 6l 034 6h l h StemTe 8l LeafOe 8h l 03 h 58 Th dplay brg out the gap the data: There are o core the hgh 70'. 7. Number Nocoformg Frequecy RelatveFrequecy(Freq/60) doe't add eactly to becaue relatve frequece have bee rouded.00 b. The umber of batche wth at mot 5 ocoformg tem , whch a proporto of 55/60.7. The proporto of batche wth (trctly) fewer tha 5 ocoformg tem 5/ Notce that thee proporto could alo have bee computed by ug the relatve frequece: e.g., proporto of batche wth 5 or fewer ocoformg tem - ( ).6; proporto of batche wth fewer tha 5 ocoformg tem - ( ).866. c. The followg a htogram of th dat The ceter of the htogram omewhere aroud or 3 ad t how that there ome potve kewe the dat Ug the rule of thumb Eerce, the htogram alo how that there a lot of pread/varato th dat Relatve Frequecy Number

3 3. 30 Percet brktgth The htogram kewed rght, wth a majorty of obervato betwee 0 ad 300 cycle. The cla holdg the mot obervato betwee 00 ad 00 cycle. b Dety brktgth c [proporto 00] [proporto < 00] , ~ 8. The mea larger tha the meda, but they are tll farly cloe together. b. Chagg the oe value, 8. 7, ~ 8. The mea lowered, the meda tay the ame. tr or 7% trmmed from each tal. c.. 0 d. For 3, Σ (.76) 3,557 For 4, Σ, ,76 or

4 35. The ample mea (00.4/8).55. The ample ze ( 8) eve. Therefore, the ample meda the average of the (/) ad (/) + value. By ortg the 8 value order, from mallet to larget: , the forth ad ffth value are ad 3. The ample meda ( )/.5. The.5% trmmed mea requre that we frt trm (.5)() or value from the ed of the ordered data et. The we average the remag 6 value. The.5% trmmed mea 74.4/6.4. tr(.5) All three meaure of ceter are mlar, dcatg lttle kewe to the data et. b. The mallet value (8.0) could be creaed to ay umber below.0 (a chage of le tha 4.0) wthout affectg the value of the ample med c. The value obtaed part (a) ca be ued drectly. For eample, the ample mea of.55 p could be re-epreed a k. p (.55 p) 5.70k , ~. 35,. 46 tr( 0) choce becaue of the outler... The meda or the trmmed mea would be good l o ~ ( ).00 b..34 ca be decreaed utl t reache.0(the larget of the mddle value).e. by , If t decreaed by more tha.383, the meda wll chage b.. 70 proporto of uccee 5. c. 80 o (0.80)(5) 0 total of 0 uccee of the ew car would have to be uccee

5 44. rage b. ( ) ( ) ( ) 0 ( ) ( ) 0, ( ) c ( ) / 0,07.4 (30.3) /0 d The ample mea, (,6) 6. The ample tadard devato,. ( ) (,6) 40, O average, we would epect a fracture tregth of 6.. I geeral, the ze of a typcal devato from the ample mea (6.) about Some obervato may devate from 6. by more tha th ad ome by le ad 368, 50, o [368,50 (563) /] ad c b. If y tme mute, the y c where 60, o y c.35 ad y c

6 57..5(IQR).5( ) 3. ad 3(IQR) 3( ) 6.4. Mld outler: obervato below or above Etreme outler: obervato below or above Of the obervato gve, 5.8 a etreme outler ad 50. a mld outler. b. A boplot of th data appear below. There a bt of potve kew to the data but, ecept for the two outler detfed part (a), the varato the data relatvely mall. * * y y a y ( a + b) ( y y) ( a + b ( a + b) ) ( a a) ( ) a. a + b a + b. b. C, y F y 5 ( 87.3) y y ( ) 5 (.04)