Test 4 - test04_s

# 1955 p ue val 0 000013 cc oncl on d eci w het usi de

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Unformatted text preview: . at st cs he val t estst i i = at st c 4. 1955 P - ue = val 0. 000013 ( c)C oncl on. D eci w het usi de her t rej o ect t nul hypot he l hesi and i erpret t deci on i t s, nt he si n he cont extof t ori nalcl m . he gi ai hat i s,w e concl ude hat t m ean pul rat for he se e Sol i ut on: Si nce P = 0. 05,w e rej ect H 0 ;t sm okers i great t s er han t hatof non- okers. sm 10 ( pts) 10.A st udy w as conduct t det ed o erm i i he sal es ofel ent ne ft ari em ary schoolt eachers f rom t o nei w ghbori di ri s w ere equal sam pl of15 t ng st ct .A e eachers from each di ri st ctw as random l sel ed.The y ect m ean f rom t ﬁrst di ri w as \$28, he st ct 900 w i h a st t andard devi i of \$2300. The m ean f at on rom t he second di ri w as \$30, st ct 300 w i h a st t andard devi i of \$2100. Test t cl m t at on he ai hat t sal es he ari f rom bot di ri s are equal A ssum e t h st ct . hatt vari he ances of t t o popul i he w at ons are equaland t he popul i at ons are norm aly di ri ed.U se = 0. l st but 05 H 0 :µ 1 = µ 2 H a :µ 1 = µ 2 w here, ari he eachers from t ﬁrstdi ri ” he st ct µ 1 = “sal es of t t ari he eachers from t second di ri ” he st ct µ 2 = “sal es of t t ( a)St e t t at he est t be appled;answ er by i cat ng w hi t o i ndi i ch est you w ilappl on your cal at l y cul or, f exam pl 1:ZTEST. or e A pplcabl t : i e est 4:2-SampTTEST ( b)Run t t he estand reportbot t t h he estst i i and t P - ue. at st cs he val t estst i i = at st c − 1. 7410 P - ue = val 0. 0927 ( c)C oncl on. D eci w het usi de her t rej o ect t nul hypot he l hesi and i erpret t deci on i t s, nt he si n he cont extof t ori nalcl m . he gi ai hat i here i i s,t s nsu Sol i ut on: Si nce P > = 0. 05,w e fai o rej lt ect H 0 ;t t hatt m ean sal es are di erentbet een t t o di ri s. he ari w he w st ct D at x 1 = 28900,s1 = 2300,n 1 = 15,¯2 = 30300,s2 = 2100,n 2 = 15. a: ¯ x ci ent evi dence t say o STA 2023/T4 – Page 5 of 5 – N am e:A nsw er K ey C orrel i and R egressi at on on. 13 ( pts) 11.The dat bel are t gest i peri a ow he at on ods,i m ont n hs,of random l sel ed ani al and t r cory ect ms hei respondi lf spans,i years. ng i e n G est i at on,x Li e span,y f 8 30 2. 1 12 1. 3 6 1 3 11. 5 25 5. 3 12 3. 8 10 24. 3 40 ( 5 pt a)( s)Cal at t correl i coe ci ,r. cul e he at on ent r 0. 9160 ( 5 pt b)( s)Fi t equat on of t regressi lne for t gi nd he i he on i he ven dat a. ˆ y= 1,5230x + 6. 3425 ( 3 pt c)( s)U se t ﬁt ed regressi lne t predi he lf span ofan ani alw i h a gest i peri he t on i o ctt ie m t at on od of 10 m ont hs. Predi ed lf span = ct ie 21. 5711...
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## This document was uploaded on 02/23/2014.

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