Question

Name: UU Please remember to show your work and write clearly. Getting a wrong answer does not mean you will lose all of the points on the question, if your procedures are correct. Also, please clearly indicate your final answer to each question. There are 6 questions for 15 points each (and ten free points). 1. A major company would like to assess the impact of using a professional trainer to conduct a confidence-building workshop with its salespeople. A sample of 16 workers is obtained. Half (n = 8) attend the workshop and the other half (n = 8) serve as a control group. Two weeks later, each of the participants is given a questionnaire measuring the level of self- confidence. The data are as follows: Controls M = 17.5 SS = 100 Workshop M = 22.7 SS = 124 a. Conduct a test to determine if there is a statistical difference between the two samples (is there a statistically significant effect?). Perform a two-tailed test, with an alpha of .05. (please show your work, including the t critical value). Controls workshop M -17.5 Mua2.7 56=100 dF=7 M=16 ss clau df=7

Answer 1

Hypothesis is w there no signiticant di Herence be 1o-condidence beelding this those have a attaned workshop f those have seare as a control group. ie. Uw = 4c Ha Thepen des significant ditterence in contidence bulding in those have tee attained workshop & those havod attato serve as a control group. ie. Uw fillo conducting t-test for mean at مو= ه test is too Given Flow=200 ] 0, 2 8 S5 = 124 tecibor > Lott ot 129 = 17.5 ron ng=8_ SS =100 Test Statistics : ( X Teala (Xw - -U) LT XLettnine-2 tito consider Um=bc=t 8² . [Cxw=*]{+ (xp-?] santos I 124 +1007 07, +n2-2 8.t -2 L

3 = 16 Ical 2917-1915 wa Tcal 5.2 470. Se Teat= -2.6.2017 tteeb = 2.1447 Decision Ttab < Teal a pejeet Ho. at 51 ticomcer resta level of signi. # conclusion 1. There is significant difference bern those worker attain wolle shop those have serve Goup. zeat meat. control group. you

bet confidence internLTQ30.05 = -742 <1 < Tanz]=105 Ef Tale f(x - Ec)-(ly-ulo) | X- ) - ག ་ ཡོ ་པ་དག་པ་ཡིན་ན་ཤ་ལན་མི་ - ( +72)4 Tales that the total weet this 5-7 - To.ozs 4 mathet 52 T - 591 Tilmed [1.6774 < elm-4cc 9.006 ] = oar = [1169.744 9. orro L E This as the contidence contidence revel. interra . conner din The meam difference is -5-2 - reem difference aso2 13 1 strandor deviation

etective sample size a 1.3 Here we we two Be independent sample t-test Independent sample t-test is use for Ca sông Hye deo sec98) In this example we check out company oigem ise the contidence bulding : 220929 t hey won't the Incredoe confidence level of worker they carry out two and thead ment- take sample size 16 e divide into group jst group apply 1st treet. ment - test group worker they do Wollshop tot inezease contidence level f second group serve as cartout conzelzoep atestate the test check. two tes treatment have same effeat. but hele our assumption will wrong. means Inul mypothesis is wrong & they Il differe became the tar Ncell hypothesis rejected after testing & the Icon tidence interval is [ 1.6774, 9-02:267I the elective sample size is 1.3 ie coherisd