Stat 217 – HW 6

Due Tuesday, Feb. 24

Note: You may want to keep a copy of your work for review for the exam.

You use the Test of Significance Calculator applet to perform calculations for these problems, but INCLUDE copies of your individually generated output.

1) Activity 20-14 (p. 406)

In (d) remember to include all 6 steps of a test of significance. The “significance level” just tells you what to compare the p-value to in order to decide whether it is small.

Hint: “All components of ta test” includes the 6 steps: parameter, hypotheses, technical conditions, test statistic, p-value, and conclusion. If you don’t have enough information to check the technical conditions explain what you would need to know.

2) Continuation of previous activity

(a) Produce a 95% confidence interval for the population parameter using the information in 20-14.

(b) Write a one-sentence interpretation of this interval.

(d) Suppose all the students added one year to their guess. How would that affect the sample mean and sample standard deviation? How would that affect the midpoint and width of the interval in (a)? Explain your reasoning and/or include appropriate calculations.

3) Activity 22-14 (p. 455-6) parts (e)-(h) using the data table above (e) and then add

(i) Calculate and interpret a 95% confidence interval for the parameter.

In (e), be sure to state the hypotheses in symbols and in words (make sure your symbols are clearly defined)

[You do not need to complete parts (a)-(d) but use the data table after (d).]

After Monday

4) Activity 21-11 (p. 431) but replace part (c) with

(c) Discuss how a 95% confidence interval for would compare.

5) Activity 21-25 (p. 436)

In (b), include all 6 steps of a test of significance. Be sure to continue in this problem even if you do not feel the technical conditions are met. In (c) and (d) you can focus on computing the p-value and conclusion (you don’t have to do all 6 steps again).