1. Intro to Stats and Collecting Data

In the context of AP Statistics Unit 3, which of the following best describes the purpose of a scatterplot?

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 15 using all of the time/tip data from the 703 taxi rides listed in Data Set 32 “Taxis” from Appendix B.

"Designing an Experiment Researchers want to know ifthere is a link between hypertension (high blood pressure) andconsumption of salt. Past studies have indicated that theconsumption of fruits and vegetables offsets the negative impactof salt consumption. It is also known that there is quite a bit ofperson-to-person variability in the ability of the body to processand eliminate salt. However, no method exists for identifyingindividuals who have a higher ability to process salt. The U.S.Department of Agriculture recommends that daily intake of saltshould not exceed 2400 milligrams (mg). The researchers wantto keep the design simple, so they choose to conduct their studyusing a completely randomized design.

How many treatments would you recommend? Why?"

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.”

b. Is the value of 85% a statistic or a parameter?

What does it mean if r = 0?

Discrete/Continuous Data Which of the following describe discrete data

c. The exact times that randomly selected students spend on smart phones during the preceding week

You collect the test scores of every other student in a class. Is this data set a population or sample?

In Exercises 21–28, determine which of the four levels of measurement (nominal, ordinal, interval, ratio) best describes the given data.

College Students In order to better plan for the incoming freshman class, a college dean asks each newly admitted student to identify their likely major (physics, business, math, psychology, engineering, law, etc.).

Response and Predictor Variables Using all of the Tour de France bicycle race results up to a recent year, we get this multiple regression equation: Speed = 29.2-0.00260Distance + 0.540Stages + 0.0570Finishers, where Speed is the mean speed of the winner (km/h), Distance is the length of the race (km), Stages is the number of stages in the race, and Finishers is the number of bicyclists who finished the race. Identify the response and predictor variables.

In Exercises 1 and 2, use the following wait times (minutes) at 10:00 AM for the Tower of Terror ride at Disney World (from Data Set 33 “Disney World Wait Times” in Appendix B).

35 35 20 50 95 75 45 50 30 35 30 30

h. Are the wait times discrete data or continuous data?

In Exercises 37–44, answer the given questions, which are related to percentages.

Percentages in Advertising In an actual ad for the Club, a device used to discourage car thefts, it was stated that “The Club reduces your odds of car theft by 400%.” What is wrong with this statement?

Survey Which of the following best describes the level of measurement of the numbers 1, 2, 3, . . . , 410 described in Exercise 1: nominal, ordinal, interval, ratio?

Percentages

c. In a Pew Research Center poll on driving, 331 of the 1182 respondents said that driving is a chore. What percentage of respondents said that driving is a chore?

A study showed the same level of T cell production in senior citizens who are amateur cyclists as in young adults, but a significantly lower level of T cell production in senior citizens who do not exercise regularly. Is it appropriate to infer that exercise stimulates T cell production? Explain. (Source: University of Birmingham)

Exercises 1–10 are based on the following sample data consisting of costs of dinner (dollars) and the amounts of tips (dollars) left by diners. The data were collected by students of the author.

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Change in Scale Exercise 1 stated that for the given paired data, r = 0.846. How does that value change if all of the amounts of dinners are left unchanged but all of the tips are expressed in cents instead of dollars?