The melting point of each of 16 samples of a certain brand o

The melting point of each of 16 samples of a certain brand of hydrogenated vegetable oil was determined, resulting in a sample mean of 94.32. Assume that the distribution of melting point is normal with = 1.20.

Test H0:=95 versus Ha:95 using a two-tailed level .01 test.

The computed value of the test statistic is:

The null hypothesis will be rejected if the computed value of the test statistic is greater than or equal to:

The null hypothesis will be rejected if the computed value of the test statistic is greater than or equal to :

Solution

              
As we can see, this is a    two   tailed test.      
              
              
Getting the test statistic, as              
              
X = sample mean =    94.32          
uo = hypothesized mean =    95          
n = sample size =    16          
s = standard deviation =    1.2          
              
Thus, z = (X - uo) * sqrt(n) / s =    -2.266666667 [ANSWER, TEST STATISTIC]

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Thus, getting the critical z, as alpha =    0.01   ,      
alpha/2 =    0.005          

zcrit =    2.575829304      

Thus, The null hypothesis will be rejected if the computed value of the test statistic is greater than or equal to 2.575829304. [ANSWER]

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