2. (8 points) make Confidence Interval for the mean of the variable from your Personal Data Set.

Go back to your Assignment 4 document (or go to Stat Crunch) and get the summary table for your original variable. Also, get the summary table for your sampling distribution where n=9. Paste both sets of summary statistics below.

a) Paste your summary tables in place of mine below. Are the mean and standard deviation of your sampling distribution close to and /n of your original variable?

https://covid19.who.int/table

b) Take a random sample of size n=9 (this is like taking one of the samples from your sampling distribution above), and calculate the sample mean, x-bar. (Note: if the distribution of your original variable was not normal, then according to the Central Limit Theorem, you should be taking a sample size of n > 30 to work exercise. However, your personal data set may not be large enough to do that, and you have better things to do, so go ahead and complete the following steps to create confidence interval for the mean of your variable using a random sample size of n = 9).

to do

Use this Random Number Generator: http://stattrek.com/statistics/random-number-generator.aspx to take a simple random sample of size n = 9 individuals from your personal data set. Put in 1 as your minimum value, and however many individuals you have in your personal data set as your maximum Change "Allow duplicate entries" to False.

Which nine random numbers have been selected for your sample? Replace my output below with yours

c) Each random number corresponds to a data point in your personal data set. For each data point, name the corresponding individual and the value of the variable.

d) Figure out the sample mean (x-bar) of your numerical variable from this sample of nine individuals. SHOW YOUR WORK, and give your answer including units of measure.

e) Use your sample mean to create 95% confidence interval for the population mean, using the standard deviation of your sampling distribution as /n. Show your work.

f) What is the mean of your population from your summary table above (this is your true population mean )? Is this mean inside or outside the limits of your confidence interval?

g) Read about the correct and incorrect ways to interpret a confidence interval on p.301, and then answer this question: If you took 20 samples and created a 95% c.i. for for each one, for how many of these confidence intervals would you expect your true mean to fall inside the limits (assuming your sample size is large enough for your sampling distribution to be normal)? Why?

3. (4 points) MyStatLab Homework 5 Problem 7 (continued)

After completing Problem 7 in MyStatLab Homework 5 ("Effectiveness of Garlic for Lowering Cholesterol") and viewing the slides on the Four Step Process, apply the four steps (STATE, PLAN, SOLVE, CONCLUDE) as described below and show your work for that problem. Be sure to put your answers in your WORDS, don't just copy the wording from MyStatLab.

a) Step 1 - STATE: Write down the question you are going to answer. Use a complete sentence which is stated in your words in the form of a question, in terms of this particular problem (garlic and cholesterol).

b) Step 2 - PLAN: Decide what type of test you will do and why, and determine the level of significance. Identify the Null and Alternative Hypotheses. For this step, write each hypothesis in symbols AND in words, using complete sentences to say what each hypothesis means in terms of this problem.

c) Step 3 - SOLVE: Calculate the test statistic and find the p-value. SHOW YOUR WORK on the calculations (this means show all the steps, in numbers, for how you would do the problem if you didn't have a computer, as you will be doing on the final exam), and say how you would use the t-table to find the p-value. Check your work by doing the same t-test in Stat Crunch, and include the computer output from the significance test.

d) Step 4 - CONCLUDE: Say whether you reject or do not reject the null hypothesis (based on the p-value from Step 3), and give the evidence for your decision. Write your own conclusion in a complete sentence in terms of the problem. Hint: your conclusion is the answer to the question you pose in Step 1.

4. (4 points) MyStatLab Homework 5 Problem 8 (continued)

After completing Problem 8 in MyStatLab Homework 5 ("Estimating the Length of a Minute") and viewing the slides on the Four Step Process, apply the four steps and show your work for that problem. Put all answers in your words.

To turn in your assignment:

Number your answers and put them in order on your Assignment #5 document, and upload your assignment to the Assignment #5 Folder.