{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

421-q1-sol

# 421-q1-sol - STT 421 Summer 2008 Quiz#1 £136 l(VS-hr LAC...

This preview shows pages 1–7. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: STT 421 Summer 2008 Quiz #1 £136: l (VS-hr LAC 4-025 3‘3th One? 83 84 96 91 88 78 92 78 79 91 83 91 88 93 73 38 38 8? 82 50 42 48 42 84 81 63 98 72 69 99 a. Construct a relative frequency hi stograan for the examination scores. (use Q intervals of width 10 beginning at 3 5). 33 25 S3" G3” 75 3'3 ‘15 [03‘ b What Is the proportmn of examinees with scores greater than 85? 8 + 3/ ﬂ U... 40 30 ea c. Point out the features of the right or left? Um'modal? n-a—‘t— swmme—k‘i'c .3 10M0A¢k\ histogram. Is it symmetric? Skewed to the d WhaRis the spreagi‘ of the data? Its medlan (guess)? mf' 3 3 H qol . ' ‘0 meARon 4‘5 0: Mtg, 67—”; (9pts)Problem 2.The ages of a sample of 25 salespersons are as follows: i l 2 i i l l i l E E _/,4:r:2'1’,3’7”53.;89k€636 32734 I ' ﬁery/3545,3835 283% l 3035/31/41 54 2/6/45 I (3pts)a. Make a stemplot of this data and comment on the features of the 3 distribution. 3 l l l l E E E l l i i i i '1 as 86 2 “Wégt‘éf/ . 3 Togﬁesgﬁo-i 3 @0124ﬁ378 it 7053945 ‘i (343)3357 5 3 4 5 3 Ly -(3pts)b.Find the median, Q1, Q3(ﬁrst and third quartiles). MM'M:?:3§ (32%: Laws: 44 Q! 3 18420:; 261 ,2 ~—._:: .2, ,3 (3pts)c. Make a boxplot and comment on the features of the distribution. neg—4:I::::—J m 16241243 )“°«___.—#——°‘"‘*U€’S 4M_.—1————-+———+ Mu) a: we. right. 1\ 2a ‘3; RR 9e ' ‘ (8pts)Problem 3. Using Table A, calculate the following areas under the Standard Normal curve, N (0, 1). (thsja. To the left of z = 1.8. - // / 0.6! éLel o 4.6 D‘ij L?) (2pts)b. Between .3 = ~14 and z = 1.9 ' fl.“ 6 1‘q (2pts)c. Between 2 = ——1 0 and z 2 1 0 Between 2 *- 2 O and z 2 . . . —_ ~ . == .0. Between ”HP-“l 2: : ~3.0 and z = 3.0 (Do you recognize the 68—95—9937 rule?) weenie—@3587: 0.5329 A» “68% 2pts)d. Find a. zo such that @533 ;:#Z::::Z:::3l23;:;_ e a a 420:0“ 25—43312 2 g ==> sax waﬂwmolo - a) “'5 4:: ?(Z<Q %US )_00‘ q: 65+ 5(l18) (6pts)Problem 4. The average length of time required for a college achieve— ment test was found to equal to 65 minutes, with a standard deviation of 5 minutes. . He‘s: 0*":5'» :‘2’ x~N£es.‘5)' (3pts)a. When should the test be terminated if we wish to allow sufﬁcient time for 90% of the students to complete the test? (Assume that time required to complete th test 11 dist b ted e isnormay r111 ) (3,5: 4 21.3 o‘ l :2 ”7 i. Ur mama-6% (1pts)b. What proportion of students comlpete the test in more than 65 minutes? 0&6 DJ 35'0/{9 _..._.u-——- ___._..—. (2pts)c. What proportion of students complete the test in less then 55 minutes? Pl X< es) :‘PCZ < rig?) : Ptzamzoozzg or 2.1% Z: w;- J, / or e /T/ W - - Wstmd aviation a: X / “I,“ . 2 ...._._.__—_.—......_.....__._____._..._.....__.......mmmummnh.ﬁﬂmww*mmm (9pte)Problem 5. Let a: =rainfall volume and y =runoff volume for a partlcular location. The accompanying values were given. anmmm (3pts)a. Construct a. scatter plot and comment on the suitability of a linear relationship between a: and y. +War€ {'5 (3. 9W”? l; " “egg, \«a 01996113613qu I. -- 5 “ between 5: MA -é= 1 3 U. m 11 (3PtS)b Find :3 y and 333,3? , 1 2-: s+\___ﬂ2_______+m1\1 _CD 3 ,— Hs 1:“an 3 E5: @1935; Lt. ' 2. 6 i teen ,. 2% __._L J,_____ i ("1)(Lr3)l’ 0+2. (_ors')+('s)( (6)] 3 (e 01%)(L1.1%) ,3 (00'36303’87 (3pts)c .Find correlation r. 4 ggﬂﬁﬁi Formulae :2: 2%,52: 1 Zea—a)? 71 71—1 Standardizing a normal random variable X with mean a and standard devi— ation a: Correlation for bivariate data: 1 n Lick—:17? k—— l. _ Z( )(y y) n w 1 1 3m 3y (n — US\$33, 1": T—2 Tables Table entry for z is the area under the standard normal curve to the left of z. .0007 .0006 .0006 .0006 .0006 .0005 .0005 .0005 I 42.4 .0082 .0080 .0078 .0075 .0073 .0071 .0069 .0068 .0064 72.3 0107 .0104 .0102 .0099 .0096 .0094 .0091 .0089 .0087 .0084 —2.2 0139 .0136 .0132 .0129 .0125 .0122 .0119 .0116 .0113 .0110 —2.1 .0179 .0174 .0170 .0166 .0162 .0158 .0154 .0150 .0143 42.0 .0228 .0222 .0217 .0212 0183 —1.4 .0808 .0793 .0764 .0749 .0721 .0708 .0694 .0681 1 -— 1.3 .0968 .0951 .0918 .0901 .0869 .0853 .0838 .0823 —1.2 .1151 .1131 .1093 .1075 .1038 .1020 .1003 .0985 —1.1 .1357 .1335 .1314 .1292 .1271 .1230 .1210 .1190 .1170 —1.0 .1587 .1562 .1515 .1492 .1446 .1423 .1401 .1379 —0.4 f .3446 .3409 .3372 .3336 .3300 .3264 .3228 .3192 .3156 —0.3 g .3821 .3783 .3745 .3707 .3669 .3632 .3594 .3557 .3520 .4129 .4090 .4052 .4013 .3974 .3936 .3897 .4522 .4483 .4443 .4404 .4364 .4325 .4286 I .4920 .4880 .4840 .4801 7 .4761 .4721 .4681 | WWW Table entry for z is the area under the standard normal curve to the left of z. 0.2 5.5793 .5832 .5871 , .6179 .6217 .62557 .8849 .8869 .8888 .9032 .9049 .9066 1.1 8 .8643 .8665 .8686 1 E .9192 .9207 .9222 3.1 .9990 .9991 .9991 3.2 .9993 .9993 .9994 3.3 .9995 .9995 .9995 3.4 ¥ .9997 .9997 .9997 .8708 .8907 .9082 .9236 .9991 .9994 .9996 .9997 .8729 .8925 .9099 .9251 .9838 .9875 .9904 .9992 .9994 .9996 .9997 .5987 .6368 .8749 .8944 .9115 .9265 .9842 .9878 .9906 9929 .9992 .9994 Q9996 .9997 .8770 .8962 .9131 .9279 .9846 .9881 .9909 .9931 .9992 .9994 .9996 .9997 .9850 .9884 .9911 .9932 .9992 .9995 .9996 .9997 .6103 .6480. .8810 .8997 .9162 .9854 .9887 .9913 .9934 5 Tables 1 T—S . MW... .6141 .6517 .8830 .9015 .9177 .9857 .9890 .9916. .9936 .9993 .9995 .9997 .9998 ...
View Full Document

{[ snackBarMessage ]}

### Page1 / 7

421-q1-sol - STT 421 Summer 2008 Quiz#1 £136 l(VS-hr LAC...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online