Basic Computation: Testing m, s Unknown A random sample has 49 values.

The sample mean is 8.5 and the sample standard deviation is 1.5. Use a level of signifi cance of 0.01 to conduct a left-tailed test of the claim that the population mean is 9.2.

(a) Check Requirements Is it appropriate to use a Student’s t distribution?

Explain. How many degrees of freedom do we use?

(b) What are the hypotheses?

(c) Compute the sample test statistic t.

(d) Estimate the P-value for the test.

(e) Do we reject or fail to reject H0?

(f) Interpret the results.

Please provide the following information for Problems 11–22.

(a) What is the level of signifi cance? State the null and alternate hypotheses.

(b) Check Requirements What sampling distribution will you use? Explain the rationale for your choice of sampling distribution. Compute the value of the sample test statistic.

(c) Find (or estimate) the P-value. Sketch the sampling distribution and show the area corresponding to the P-value.

(d) Based on your answers in parts

(a) to (c), will you reject or fail to reject the null hypothesis? Are the data statistically signifi cant at level a?

(e) Interpret your conclusion in the context of the application.
Note: For degrees of freedom d.f. not given in the Student’s t table, use the closest d.f. that is smaller. In some situations, this choice of d.f. may increase the P-value by a small amount and therefore produce a slightly more “conservative”
answer.