Question

B (1 point) A professor in the school of business at a certain university wants to investigate the claim that the prices of new textbooks in the campus store are higher than a competing national online bookstore. The professor randomly chooses required texts for 12 business school courses. The data is given in the table below. Book Campus Store Online Store А 55 50.95 47.5 45.75 50.5 50.95 38.95 38.5 58.7 56.25 49.9 45.95 39.95 40.25 41.5 39.95 42.25 43 44.95 42.25 45.95 44 56.99 55.99 - IMO (a) Let X A denote the price of books at the campus store, and X 3 be the price of books at the online store, also let XD = XA-X B. Choose the correct statistical hypotheses. A. HOD=0, HAMD<0 B. Ho: Mcampus Monline HA: Mcampus Honline C. Ho : p= 0 HAWD > 0 D. HOWcampus = Honline HA Hcampus 7 Honline E. HO : Mcampus= Honline HA: Mcampus > Honline OF. HOND > 0, HACHD <0 G. HO : Mp= 0, HA: D# 0 H. Houd = 0, HAND < 0 (b) Carry out the appropriate statistical test and find the P-value, to three decimal places. P= (c) Based on the above calculations, we should ? the null hypothesis. Use a = 0.05. (d) Using the technology available to you, create the most appropriate graph(s) to check the assumption(s) that need to be satisfied for your inferences in (b) and (c) to be valid. What statement below aligns with your findings? A. The prices charged at the online bookstore are normally distributed. B. The differences in the price of a textbook at the campus bookstore and the price of the textbook at the online store are normally distributed. C. The prices charged at the online bookstore are not normally distributed D. The prices charged at the campus bookstore are normally distributed. E. The prices charged at the campus bookstore are not normally distributed. F. The differences in the price of a textbook at the campus bookstore and the price of the textbook at the online store are not normally distributed.

Answer 1

R RGui (32-bit) File Edit View Misc Packages Windows Help STOP RR Console > tx and y denote price in campus store and online store respectively > x=c(55, 47.5, 50.5, 38.95,58.7,49.9,39.95,41.5, 42.25, 44.95,45.95, 56.99) >y-c(50.95, 45 .75, 50 .95, 38 .5, 56.25, 45 . 95, 40.25, 39.95, 43,42.25, 44, 55.99) > #to test whether the prices of campus store and online store are normally > #distributed are not >shapiro.test (x) ; shapiro.test(y) Shapiro-Wilk normality test data: W =0.94239, p-value = 0.5296 Shapiro-Wilk normality test data: y W = 0.91306, p-value = 0.2335 ab #Cwo sample t-test for testing whether the price in campus store is higher > #the price in online store t.test (x,y, alternative="greater", conf.level=0.95) Welch Two Sample t-test data: x and y t = 0.58715, df = 21.817, p-value = 0.2816 alternative hypothesis: true difference in means is greater than 0 95 percent confidence interval: Inf -2.944618 sample estimates: mean of X mean of y 47.67833 46.14917 Type here to search O

XD densli dienenee in rtees belween anpeis gtane & nline 8tone epetineley We want ehech ashithen 4he dittenense gneaten taan mnot, le, le) toMD HAIMDO AiHuenee oherer o deuslis the auenage in priee im the pepulatim LLeneo Tivo sanple t tert hhll be enfrmed ebaca Tght tailed tlegt baeed on a URa tais oronld ke appreriala. naleeo of fst atatlote0.58H 5 obgerned PHo (t7obsa t) 6.2820 0-05 P-value not reject tto Baaed on this, me shonld at conaude at 6% d-o-0s, me can leuel of ignifieanee tant, tae bats of the dala tae prtee u canupo etane is mof highon than the ie iu nline slose Jhe golowing vali& for the tteet talemente dhonld Ae the pries changed et the 0nline bookelbae are menaaly dic-tni baled The priees changed at the canpuro boot slore are nonmally disti bulld diffenenies bn tha prices of a text bork at the campus loerkglove theonline store monmally dishibulid The ane

Normal Q-Q Plot -1.5 1.0 0.5 0.0 0.5 1.0 1.5 Theoretical Quantiles Sample Quantiles 55 09

Normal Q-Q Plot -1.5 1.0 0.5 0.0 0.5 1.0 1.5 Theoretical Quantiles Sample Quantiles 45 55 09

Normal Q-Q Plot -1.5 1.0 0.5 0.0 0.5 1.0 1.5 Theoretical Quantiles Sample Quantiles 2 0
the graphs are showing the fact that prices at campus store and online store, the differences in prices all are normally distributed