A study claimed residents in a suburb town spend at most 1.9 hours per weekday commuting to and from their jobs. A researcher believed commute times were now different and wants to test this claim by sampling 14 adults. Sample statistics for these 14 adults are: X = 2.2 $=0.7 Can the researcher support the claim that mean commuting time is more than 1.9 hours ? Test using a =.01.

Respuesta :

Answer:

There is no sufficient evidence to support the claim that mean commuting time is more than 1.9 hours

Step-by-step explanation:

From the question we are told that

   The  population mean is  [tex]\mu = 1.9 \ hr[/tex]

   The  sample mean is  [tex]\= x = 2.2[/tex]

    The standard deviation is  [tex]\sigma = 0.7[/tex]

     The  sample size is  [tex]n = 14[/tex]

      The level of significance is  [tex]\alpha = 0.01[/tex]

The null hypothesis is  [tex]H_o : \mu = 1.9 \ hr[/tex]

The  alternative hypothesis is [tex]H_a : \mu > 1.9 \ hr[/tex]

 Generally the test statistics is mathematically represented as

               [tex]t = \frac{\= x - \mu }{ \frac{\sigma}{ \sqrt{n} } }[/tex]

              [tex]t = \frac{ 2.2 - 1.9 }{ \frac{0.7 }{ \sqrt{14} } }[/tex]

             [tex]t = 1.6036[/tex]

The  p-value is obtained from the z-table,  the value is  

           [tex]p-value = P(t > 1.6036) = 0.054401[/tex]

Looking at the value of  [tex]p-value \ and \ \alpha[/tex]  we see that  [tex]p-value > \alpha[/tex]

So we fail reject the null hypothesis

    Hence we can conclude that there is no sufficient evidence to support the claim that mean commuting time is more than 1.9 hours