Asample of 30 observations is selected from a normal population. the sample mean is 21, and the population standard deviation is 6. conduct the following test of hypothesis using the 0.05 significance level. h0 : μ ≤ 20 h1 : μ > 20

We conclude that μ <= 20 after hypothesis testing.

Step-by-step explanation:

We are given that sample of 30 observations is selected from a normal population.

Also, Sample mean, Xbar = 21 and Population Standard deviation, = 6.

                  Null Hypothesis, : μ <=20

          Alternate Hypothesis, : μ > 20

So, Test Statistics we will use here is ;

                  follows standard normal, N(0,1)

         Test statistics = = 0.913 .

Now at 5% level of significance z % table gives the critical value of 1.6449 and our test statistics is less than this as 1.6449 > 0.913. So,we have sufficient evidence to do not reject null hypothesis or accept as our test statistics does not falls in the rejection region because it is less than 1.6449.

Hence we conclude after testing that Population mean, μ<=20.

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step-by-step explanation:

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answer: the anser is 3

step-by-step explanation:

c- 2o is equal to 9