The posted speed limit on Interstate 70 is 70 miles per hour, but it is claimed that the mean of the actual speeds ...

      The posted speed limit on Interstate 70 is 70 miles per hour,   but it is claimed that the mean of the actual speeds of vehicles is greater   than 70 miles per hour. To test this claim, the speeds of 36 randomly   selected vehicles were taken and reported to the right.   

        Speed of Randomly Selected Vehicles on I-70   68 77 65 71 77 73     62 78 68 72 77 72     74 72 74 70 76 72     73 71 75 70 70 74     75 61 74 72 69 75     84 79 83 75 71 76      

(a)       Give   the null and alternative hypotheses for this situation in mathematical   notation.    

(b)       Based upon a 10% level of significance, determine the critical   value(s) associated with this hypothesis test.      

(c)       Determine   the sample's test statistic.     

(d)      State a   final conclusion regarding the results of the hypothesis test. Make sure your statement is tied to the   context of the problem (speed of vehicles on I-70).