The values of the sample mean, sample standard deviation, and (estimated) standard error of the mean are 2.482, 1.614, and 0.295, respectively. Does this data suggest that the true average percentage of organic matter in such soil is something other than 3%

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Complete Question

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Answer:

Yes  the test  suggest that the true average percentage of organic matter in such soil is something other than 3%

 

Step-by-step explanation:

From the question we are told that

  The  sample mean is  [tex]\= x = 2.482\%[/tex]

  The  standard deviation is [tex]\sigma = 1.614[/tex]

   The  standard error is [tex]SE = 0.295[/tex]

     The  sample size is [tex]n = 30[/tex]

   The  level of significance is  [tex]\alpha = 0.05[/tex]

  The  null hypothesis is [tex]H_o : \mu = 3\%[/tex]

   The  alternative hypothesis is  [tex]H_a : \mu \ne 3\%[/tex]

Now  the degree of freedom is evaluated as

       [tex]df = n - 1[/tex]

       [tex]df = 30 - 1[/tex]

       [tex]df = 29[/tex]

The test statistics is mathematically evaluated as

         [tex]t = \frac{ 2.482 - 3}{ 0.295}[/tex]

         [tex]t = -1.756[/tex]

The p-value is obtained from the the student t -distribution table , the value is  

        [tex]p-value = P( T \le t)= 2 * t_{ t, df } = t_{ -1.756 , 29 } = 2 *0.0448= 0.0896[/tex]

The reason for the 2 in the equation is because the test is a two -tailed test i.e  -1.756 and  1.756

Given that the [tex]p-value > \alpha[/tex] then we fail to reject the null hypothesis

Hence the test the suggest that the true average percentage of organic matter in such soil is something other than 3%

   

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