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Experimental Units Identify the experimental units on which the following variables are measured: a. Gender of a student b. Number of errors on a midterm exam c. Age of a cancer patient d. Number of flowers on an azalea plant e. Color of a car entering a parking lot

Parking on Campus Six vehicles are selected from the vehicles that are issued campus parking permits, and the following data are recorded: a. What are the experimental units? b. What are the variables being measured? What types of variables are they? c. Is this univariate, bivariate, or multivariate data?

Voter Attitudes You are a candidate for your state legislature, and you want to survey voter attitudes regarding your chances of winning. Identify the population that is of interest to you and from which you would like to select your sample. How is this population dependent on time?

1.11 Jeans A manufacturer of jeans has plants in California, Arizona, and Texas. A group of 25 pairs of jeans is randomly selected from the computerized database, and the state in which each is produced is recorded: \(\begin{array}{lllll}\text { CA } & \text { AZ } & \text { AZ } & \text { TX } & \text { CA } \\ \text { CA } & \text { CA } & \text { TX } & \text { TX } & \text { TX } \\ \text { AZ } & \text { AZ } & \text { CA } & \text { AZ } & \text { TX } \\ \text { CA } & \text { AZ } & \text { TX } & \text { TX } & \text { TX }\end{array}\) CA a. What is the experimental unit? b. What is the variable being measured? Is it qualitative or quantitative? c. Construct a pie chart to describe the data. d. Construct a bar chart to describe the data. e. What proportion of the jeans are made in Texas? f. What state produced the most jeans in the group? g. If you want to find out whether the three plants produced equal numbers of jeans, or whether one produced more jeans than the others, how can you use the charts from parts \(\mathrm{c}\) and \(\mathrm{d}\) to help you? What conclusions can you draw from these data?

Want to Be President? Would you want to be the president of the United States? Although many teenagers think that they could grow up to be the president, most don't want the job. In an opinion poll conducted by \(A B C\) News, nearly \(80 \%\) of the teens were not interested in the job. \(^{2}\) When asked "What's the main reason you would not want to be president?" they gave these responses: a. Are all of the reasons accounted for in this table? Add another category if necessary. b. Would you use a pie chart or a bar chart to graphically describe the data? Why? c. Draw the chart you chose in part b. d. If you were the person conducting the opinion poll, what other types of questions might you want to investigate?

Construct a stem and leaf plot for these\(\ 50\) measurements: $$\begin{array}{llllllllll}3.1 & 4.9 & 2.8 & 3.6 & 2.5 & 4.5 & 3.5 & 3.7 & 4.1 & 4.9 \\\2.9 & 2.1 & 3.5 & 4.0 & 3.7 & 2.7 & 4.0 & 4.4 & 3.7 & 4.2 \\\3.8 & 6.2 &2.5 & 2.9 & 2.8 & 5.1 & 1.8 & 5.6 & 2.2 & 3.4 \\\2.5 & 3.6 & 5.1 & 4.8 & 1.6 & 3.6 & 6.1 & 4.7 & 3.9 & 3.9 \\\4.3 & 5.7 & 3.7 & 4.6 & 4.0 & 5.6 & 4.9 & 4.2 & 3.1 & 3.9\end{array}$$ a. Describe the shape of the data distribution. Do you see any outliers? b. Use the stem and leaf plot to find the smallest observation. c. Find the eighth and ninth largest observations.

A discrete variable can take on only the values \(0,1,\) or 2 . A set of 20 measurements on this variable is shown here: $$\begin{array}{lllll}1 & 2 & 1 & 0 & 2 \\\2 & 1 & 1 & 0 & 0 \\\2 & 2 & 1 & 1 & 0 \\\0 & 1 & 2 & 1 & 1\end{array}$$ a. Construct a relative frequency histogram for the data. b. What proportion of the measurements are greater than \(1 ?\) c. What proportion of the measurements are less than \(2 ?\) d. If a measurement is selected at random from the 20 measurements shown, what is the probability that it is a \(2 ?\) e. Describe the shape of the distribution. Do you see any outliers?

Test Scores The test scores on a 100-point test were recorded for 20 students: $$\begin{array}{lllllllllll}61 & 93 & 91 & 86 & 55 & 63 & 86 & 82 & 76 & 57 \\\94 & 89 & 67 & 62 & 72 & 87 & 68 & 65 & 75 & 84\end{array}$$ a. Use an appropriate graph to describe the data. b. Describe the shape and location of the scores. c. Is the shape of the distribution unusual? Can you think of any reason the distribution of the scores would have such a shape?

Preschool The ages (in months) at which 50 children were first enrolled in a preschool are listed below. $$\begin{array}{llllllllll}38 & 40 & 30 & 35 & 39 & 40 & 48 & 36 & 31 & 36 \\\47 & 35 & 34 & 43 & 41 & 36 & 41 & 43 & 48 & 40 \\\32 & 34 & 41 & 30 &46 & 35 & 40 & 30 & 46 & 37 \\\55 & 39 & 33 & 32 & 32 & 45 & 42 & 41 & 36 & 50 \\\42 & 50 & 37 & 39 & 33 & 45 & 38 & 46 & 36 & 31\end{array}$$ a. Construct a stem and leaf display for the data. b. Construct a relative frequency histogram for these data. Start the lower boundary of the first class at 30 and use a class width of 5 months. c. Compare the graphs in parts a and b. Are there any significant differences that would cause you to choose one as the better method for displaying the data? d. What proportion of the children were 35 months (2 years, 11 months) or older, but less than 45 months ( 3 years, 9 months) of age when first enrolled in preschool? e. If one child were selected at random from this group of children, what is the probability that the child was less than 50 months old ( 4 years, 2 months) when first enrolled in preschool?

Symmetric or Skewed? Do you expect the distributions of the following variables to be symmetric or skewed? Explain. a. Size in dollars of nonsecured loans b. Size in dollars of secured loans c. Price of an 8 -ounce can of peas d. Height in inches of freshman women at your university e. Number of broken taco shells in a package of 100 shells f. Number of ticks found on each of 50 trapped cottontail rabbits