Austin West 2/15/16 9:10 Homework: W3-Chapter 9.5&10.1-2 Score: 0 of 1 pt HWScor

Question

Austin West 2/15/16 9:10 Homework: W3-Chapter 9.5&10.1-2 Score: 0 of 1 pt HWScore: C 6 83 01 10 pts A trannportation agency wouild ike to compare the average amount of tme t takers random samples from each arpont Use the table to completle parts a wough Location 1 Locaion 2 Sample mean 142 11 5 Sample sure 24 through secunity at these tawo loc ations are equal Determine the null and atemative hypotheses for the tost Cakulato the approprate test stattc ad elepret the resu The test statisic is nd to two arma places as ) Enter your answer in the answer box and then cick Check Aeswer Check Aeswer remann

Explanation / Answer

Formulating the null and alternative hypotheses,              
              
Ho:   u1 - u2   <=   0  
Ha:   u1 - u2   >   0  
At level of significance =    0.01          
As we can see, this is a    right   tailed test.      
Calculating the means of each group,              
              
X1 =    14.2          
X2 =    11.5          
              
Calculating the standard deviations of each group,              
              
s1 =    5.5          
s2 =    4.6          
              
Thus, the standard error of their difference is, by using sD = sqrt(s1^2/n1 + s2^2/n2):              
              
n1 = sample size of group 1 =    24          
n2 = sample size of group 2 =    26          
Thus, df = n1 + n2 - 2 =    48          
Also, sD =    1.440230128          
              
Thus, the t statistic will be              
              
t = [X1 - X2 - uD]/sD =    1.874700403   [ANSWER, TEST STATISTIC]

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where uD = hypothesized difference =    0          
              
Now, the critical value for t is              
              
tcrit =        2.406581273   [ANSWER, CRITICAL VALUE]

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Also, using p values,              
              
p =    0.033462882   [ANSWER, P VALUE]      

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As P < 0.05,    WE FAIL TO REJECT THE NULL HYPOTHESIS.         

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Hi! If you use another method/formula in calculating the degrees of freedom in this t-test, please resubmit this question together with the formula/method you use in determining the degrees of freedom. That way we can continue helping you! Thanks!

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