We wish to compare the weights of the truckloads of gravel delivered by two comp
ID: 3150500 • Letter: W
Question
We wish to compare the weights of the truckloads of gravel delivered by two companies (Palatka and Jacksonville).
Perform a two sided test of the hypothesis that the average delivered weights (in tons) for the two companies are equal (based on the data below). Let the level of significance be 10%. Determine the p-value, perform the test, and state your conclusion
Construct a 90% confidence interval for the difference in average weight for the two companies.
Please show all work
Palatka
Jacksonville
2.8
2.4
3.0
2.8
2.7
2.5
2.9
2.9
2.7
2.5
2.9
2.9
2.9
2.7
3.0
2.5
2.8
Palatka
Jacksonville
2.8
2.4
3.0
2.8
2.7
2.5
2.9
2.9
2.7
2.5
2.9
2.9
2.9
2.7
3.0
2.5
2.8
Explanation / Answer
State the hypotheses:
H0: muP-muJ=0 (There is no difference in mean weights of truck loads of gravel delivered by two companies)
H1:muP-muJ not equal to 0 (There is difference in mean weight of truck loads delivered by two companies).
Perform the test:
From information given,
nP=9, xbarP=2.856, sP=0.038
nJ=8, xbarJ=2.650, sJ=0.071
For independent groups,
SE(xbarP-xbarJ)=sqrt [sP^2/nP+sJ^2/nJ]= sqrt [0.038^2/9+0.071^2/8]=0.0281
t=(xbarP-xbarJ)-0/SE(xbarP-xbarJ)=(2.856-2.650)-0/0.0281=2.57
At df=10, the p value is 0.028.
The p value is less than 0.1, therefore, reject null hypothesis to conclude that there is significant difference in weights of truckloads of gravel delivered by two companies.
90% c.i=(xbarP-xbarJ)+-ME=(2.856-2.650)+-0.0509=0.206+-0.0509=0.1551 to 0.2569
[ME=t*10*SE(xbarP-xbarJ)=1.812*0.0281=0.0509]
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.