Can you help me with these 3 questions and what table do the

Solution

3.

Formulating the null and alternative hypotheses,              
              
Ho:   u   <=   50  
Ha:    u   >   50  
              
As we can see, this is a    right   tailed test.      
              
Getting the test statistic, as              
              
X = sample mean =    49.4          
uo = hypothesized mean =    50          
n = sample size =    100          
s = standard deviation =    4.1          
              
Thus, z = (X - uo) * sqrt(n) / s =    -1.46          
              
Also, the p value is, as this is right tailed,              
              
p = 0.9279 [ANSWER]

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P = 0.9279 means that if the null hypothesis is true, the probability of getting a sample at least this far to the right of the population mean is 0.9279.

Thus, there is much reason to believe that the mean is not greater than 50 (the sample mean itself is not greater than 50!)

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In table 3, they use the Standard Normal Distribution Table.

However, as tables usually give the left tailed areas, be careful to get the complement of the area of z < -1.46 to get the correct p value.

The left tailed area of -1.46 is 0.0721. Hence, the complement is the P value, 1 - 0.0721 = 0.9279. [CONCLUSION]              
  

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