Question

nna's project for her introductory statistics course was to compare the seling prices of textbooks at two Ieternet bockstores She ist ook a randam sample of ton toatbooks used that se he list of exts compiled by the coliege bookstore. The prices of those textbooks at the two Intamet sites ane shown below Complete parts a through c in courses at her college, based eA $115 $79 $41 $137 99 $31 $85 $s8 $118 $69 ite B $110 $79 $38 $129 $99 $31 $69 $98 $108 $68 Are these independent samples or dependent samples? Justfy your answer. Choose the correct answer below A The samples ane independent because diferent books are used for the two samplers The samples are dependent because different books are used for the two samples C. The samples are independent because the same books are used for each sample "D The samples ยข dependert because he same books are used for each sample Find he meanfor each sample. Find se mean of the dhrerce sooros. wire te de moe hepnce at Sito Amr te pree at Sta BCompre and repre ind the mean for the sample from Site A $ 872 ind the mean for the sample from Ste B $ 82.7 ind the mean of the diference scores, where the difference is the price at Site A minus the price at She B e$45 ompare, and interpret. Choose the comect answer below The mean torsae A is geater than te mean for Sto B. Thus, the mean ofte dnereron scoms is negawe The mean took pren at Ste 8%less tar, at Ste A. " The mean sor Site A is less ran ge m for Ste B Thus, te mean of the dmerene scores spsiive The mean took proe at Ste B s less han asse A. C The mean for Ste A is ess ran ne-, for Sie B Thus, the mean of the dierence scores sregatve. The mean book price at Sto А is iess than at Sen B The mean for Site A is greaner than the mean for Site B. Thus, the mean of the cifference scores is postive. The mea book price at Sihe B is lnss than at Site A lick to select and enter your answeris) and then click Chock Answr

need answer for c

Answer 1

Answer)

First we need to estimate the standard deviation of both the sites

Site A : S1 = 33.5884

Site B : S2 = 31.9376

N1 = N2 = 10

First we need to find the margin of error

Margin of error = t*standard error

Degrees of freedom is = smaller of n1-1, n2-1

Here in this case degrees of freedom is = 9

And confidence level is 90%

From t table, t = 1.833

STANDARD ERROR = √{(S1^2/N1)+(S2^2/N2)}

after substituting the values

Margin of error (MOE) = 26.8657458537

Confidence interval is given by

(Mean difference - MOE, mean difference + MOE)

(−22.365745853, 31.3657458537)

(-22.366, 31.366)