1. Intro to Stats and Collecting Data

Green Tea You wonder whether green tea lowers cholesterol.

Explain how you woold use blinding in this experiment.

In Exercises 5–8, use the following two control charts that result from testing batches of newly manufactured aircraft altimeters, with 100 in each batch. The original sample values are errors (in feet) obtained when the altimeters are tested in a pressure chamber that simulates an altitude of 6000 ft. The Federal Aviation Administration requires an error of no more than 40 ft at that altitude.

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Is the process variation within statistical control? Why or why not?

For which of the following $\mathrm{population}\mathrm{parameters}$ is $\mathrm{sampling}$ not necessary?

In Problems 17–20, (b) by hand, compute the correlation coefficient, and (c) determine whether there is a linear relation between x and y.

Which of the following best describes the difference between $\mathrm{univariate}$ data and $\mathrm{bivariate}$ data?

College Survey In a national survey conducted by the Centers for Disease Control to determine health-risk behaviors among college students, college students were asked, “How often do you wear a seat belt when riding in a car driven by someone else?” The frequencies were as follows:

g. Suppose that a representative from the Centers for Disease Control says, “52.7% of college students surveyed always wear a seat belt.” Is this a descriptive or inferential statement?

Effects of an Outlier Refer to the Minitab-generated scatterplot given in Exercise 9 of Section 10-1

a. Using the pairs of values for all 10 points, find the equation of the regression line.

Examine the following p chart for defective calculator batteries and briefly describe the action that should be taken.

Cell Phone Radiation. Listed below are amounts of cell phone radiation (W/kg) measured from randomly selected cell phones (based on data from the Federal Communications Commission). Use these values for Exercises 1–6.

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Level of Measurement What is the level of measurement of these data (nominal, ordinal, interval, ratio)? Are the original unrounded amounts of radiation continuous data or discrete data?

Researchers Katherine Tucker and associates wanted to determine whether consumption of cola is associated with lower bone mineral density. They looked at 1125 men and 1413 women in the Framingham Osteoporosis Study, which is a cohort that began in 1971. The first examination in this study began between 1971 and 1975, with participants returning for an examination every 4 years. Based on results of questionnaires, the researchers were able to determine cola consumption on a weekly basis. Analysis of the results indicated that women who consumed at least one cola per day (on average) had a bone mineral density that was significantly lower at the femoral neck than those who consumed less than one cola per day. The researchers did not find this relation in men.

e. Can you think of any lurking variables that should be accounted for?

Paying for First Dates USA Today posted this question on the electronic version of its newspaper: “Should guys pay for the first date?” Of the 1148 subjects who decided to respond, 85% of them said “yes.”

c. Does the survey constitute an experiment or an observational study?

Treatment for Osteoporosis Osteoporosis is a condition in which people experience decreased bone mass and an increase in the risk of bone fracture. Actonel is a drug that helps combat osteoporosis in postmenopausal women. In clinical trials, 1374 postmenopausal women were randomly divided into experimental and control groups. The subjects in the experimental group were administered 5 milligrams (mg) of Actonel, while the subjects in the control group were administered a placebo. The number of women who experienced a bone fracture over the course of one year was recorded. Of the 696 women in the experimental group, 27 experienced a fracture during the course of the year. Of the 678 women in the control group, 49 experienced a fracture during the course of the year.  

a. What type of experimental design is this? What is the response variable? Is it qualitative or quantitative? What are the treatments?  

Large Data Sets

Exercises 29–32 use the same Appendix B data sets as Exercises 29–32 in Section 10-1. In each case, find the regression equation, letting the first variable be the predictor (x) variable. Find the indicated predicted values following the prediction procedure summarized in Figure 10-5.

Taxis Repeat Exercise 16 using all of the distance/tip data from the 703 taxi rides listed in Data Set 32 “Taxis” from Appendix B.

In statistics, what is the collection of all observations or measurements on the variables called?