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Data Set

1.

What is the mean breaking strength?

2.

How many of the pieces of wood have strengths less than the mean?

3.

Below is a stemplot describing the distribution of breaking strengths. What feature of the stemplot explains the fact that the mean is smaller than most of the observations?

4.

(1.06) Where are older Americans more likely to live? Table 1.2, below, below gives the percent of residents aged 65 years and over in each of the 50 states and the District of Columbia. Make a histogram of the percent using classes of width 1% starting at 7%. That is, the first bar covers 7.0% to 7.9%, the second covers 8.0% to 8.9%, and so on. Select the bar graph that correctly presents the data.

(1.09) Figure 1.9 shows the distribution of the state percents of women aged 15 and over who have never been married.

Data Set

5.

The main body of the distribution is slightly skewed to the right. There is one clear outlier, the District of Columbia. Why is it not surprising that the percent of never-married women is higher in DC than in the 50 states?

6.

The midpoint of the distribution is the 26th largest (or smallest) value in order of percent of never-married women. In which class does the midpoint fall?

7.

About what is the spread (smallest to largest) of the distribution?(ignoring the outlier).

Until Congress allowed some enforcement in 2002, the thousands of foreign diplomats in New York City could freely violate parking laws. Two economists looked at the number of unpaid parking tickets per diplomat over a five-year period ending when enforcement reduced the problem. They concluded that large numbers of unpaid tickets indicated a "culture of corruption" in a country and lined up well with more elaborate measures of corruption. The data set for 145 countries is too large to print here, but look at the data file on the text Web site and CD.

Data Set The first 32 countries in the list (Australia to Trinidad and Tobago) are classified by the World Bank as "developed." The remaining countries (Albania to Zimbabwe) are "developing." The World Bank classification is based only on national income and does not take into account measures of social development. Give a full description of the distribution of unpaid tickets for both groups of countries and identify any high outliers. Compare the two groups. Does national income alone do a good job of distinguishing countries whose diplomats do and do not obey parking laws? Follow the four-step process in reporting your work.

8.

State: Which of the options below clearly states the practical question we are trying to answer?

9.

Plan: Which of the options below clearly states the statistical operations that this problem calls for?

10.

Solve: What should be the first step in your statistical analysis?

11.

As part of the solving process make stemplots for the two distributions. Which of the following descriptions match your findings?

12.

Which of the following numerical descriptions is the most appropriate choice for these distributions?

13.

Give the five-number summary of the distribution of the developed countries diplomats. Match your results below:

14.

Give the five-number summary of the distribution of the developing countries. Match your results below:

15.

Conclude: What is your conclusion based on your statistical analysis?

16.

The respiratory system can be a limiting factor in maximal exercise performance. Researchers from the United Kingdom studied the effect of two breathing frequencies on both performance times and several physiological parameters in swimming. Subjects were 10 male collegiate swimmers. Here are their times in seconds to swim 200 meters at 90% of race pace when breathing every second stroke in front-crawl swimming:

The standard deviation of the 10 swim times is about 8.2. The correct units for the standard deviation are

17.

Which of the following is least affected if an extreme high outlier is added to your data?

18.

(1.21) How long must you travel each day to get to work? Here is a stemplot of the average travel times to work for workers in the 50 states and the District of Columbia who are at least 16 years of age and don’t work at home. The stems are whole minutes and the leaves are tenths of a minute. The center of the distribution in the data above is close to Data Set

19.

(1.22) You look at real estate ads for houses in Naples, Florida. There are many houses ranging from $200,000 to $500,000 in price. The few houses on the water, however, have prices up to $15 million. The distribution of house prices will be

(1.24) How can we help wood surfaces resist weathering, especially when restoring historic wooden buildings? In a study of this question, researchers prepared wooden panels and then exposed them to the weather.

20.

Here are some of the variables recorded. Which of these variables are categorical and which are quantitative?

(1.29) The National Survey of Student Engagement asked students at many universities, "How would you evaluate your entire educational experience at this university?" Here are the percents of senior-year students at Canada's 10 largest primarily English-speaking universities who responded "Excellent":

21.

The list is arranged in order of undergraduate enrollment. Make a bar graph with the bars in order of student rating.

22.

Select the most appropriate explanation why it is not correct to make a pie chart of these data.

Place five observations on the line in the Mean and Median applet by clicking below it.

23.

Add one additional observation without changing the median. Where is your new point? In order for you to answer, number the original five points from left to right. Indicate between which points you placed your sixth point. If you placed it exactly on a certain point, then indicate that you placed it between that point and itself.

24.

Use the applet to convince yourself that when you add yet another observation (there are now seven in all), the median does not change no matter where you put the seventh point. Explain why this must be true.

25.

26.

Select the correct choice. "Suppose we want to estimate the average number of chocolate chips per cookie in a batch of cookies. The collection of all cookies in the batch is known as the ____."

Reference: StatClips: Statistics Introduction

27.

True or False: We are allowed to remove records that do not appear to fit in with the rest of the data to create a more uniform data set.

Reference: StatClips: Basic Principles of Exploring Data

28.

Select the correct choice. If a histogram is considered “skewed left” which value will be greater, the median or mean?

Reference: StatClips: Exploratory Pictures for Quantitative Data

29.

Select the correct choice. "If you plan to work with data in your career, you need to learn something about _____."

Reference: Snapshots: Statistics Introduction