Question

A employees claims that the population mean of weight of ANC company is NOT 58kg. A random sample of 25 is tested and the sample mean is 62kg. Assume the weight is normally distributed with the population standard deviation 2.8kg. We will do a hypothesis testing at 5% level of significance to test the claim.

1. (a) (10) Set up the null hypothesis and alternative hypothesis.

2. (b) (5) Which test should we use? Upper-tailed test? Lower-tailed test? Two-tailed

   test?

3. (c) (10) Find the Z-value of the test statistic.

4. (d) (5) Find the p-value for the test statistic.

5. (e) (10) Explain the meaning of p-value.

6. (f) (10) Should we reject the null hypothesis? Use the result of (d) to explain the

   reason.

Answer 1

a. Here claim is that mean is not 58 kg

So hypothesis is vs

b. Here population standard deviation is known so we will use z test statistics and it is two tailed test.

c.

d. P value is

e. P value is the probability of getting test results as extreme as the output actually observed during the test, expecting that the null hypothesis is correct.

f. As P value is less than alpha=0.05, we reject the null hypothesis