Exam 5: Statistical Reasoning

Create a graphical display for the data given. You may choose any graphic type that you feel is appropriate. Write a fewsentences explaining why you chose this type of display and a few sentences describing any interesting patterns in thedata. -The table below shows the population of the United States in 2000 broken down by age and gender. Population is given in millions. Age Female Male 0-9 19.4 20.3 10-19 19.9 21.0 20-29 18.9 19.6 30-39 21.6 21.7 40-49 21.6 21.1 50-59 16.1 15.3 60-69 10.8 9.6 70-79 9.3 7.0 80+ 6.5 3.1

Use the guidelines to evaluate the study. From the information given, what is the biggest flaw in the study? -You would like to know if the customers of your video store are satisfied. You hand a customer satisfaction questionnaire to every customer who comes into the store and ask them to fill it out And place it in a box after they check out. The questionnaire asks customers to rate their satisfaction On a scale of 1-10 with regard to the video selection and customer service.

In order to answer the given question, which of the following types of study would be the most appropriate: anexperiment without blinding, an experiment with single blinding, an experiment with double blinding, an observationalstudy, or a case-control study? -Can acupuncture relieve anxiety? [The level of anxiety at any given time will be determined by interviewing the patient. The interviewer will be a person other than the acupuncturist.]

Provide an appropriate response. -The ages of employees of a company are summarized in the frequency table. Age Frequency 18-24 11 25-31 38 32-38 35 39-45 27 46-52 22 53-59 14 60-66 5

State whether you think that the variables have strong positive correlation, weak positive correlation, strong negativecorrelation, weak negative correlation, or no correlation. -Number of siblings and number of pairs of shoes owned by children

A statement is made about correlation. State whether the correlation is positive or negative and whether the correlation ismost likely due to coincidence, a common underlying cause, or a direct cause. -People who drive faster, cover the distance in a shorter time.

Answer as requested. -Which of the following pairs of variables is likely to have no correlation?

Answer the question. -Which of the following describes a study in which the researchers do not attempt to change the characteristics of those being studied?

State whether you think that the variables have strong positive correlation, weak positive correlation, strong negativecorrelation, weak negative correlation, or no correlation. -Actual temperature on a given day and the temperature that had been forecast for that day 10 days previously.

Use the indicated bin size to construct a frequency table for the set of data. Include columns for relative frequency andcumulative frequency. -The ages of 25 patients who suffered strokes are as follows. 69 72 46 81 45 50 57 61 48 56 77 58 74 73 80 47 53 60 58 46 61 66 55 79 84 Use 5 -point bins $( 45 - 49,50 - 54$ , etc)

Use the graph to answer the question. -The bar graph below shows the relative frequencies of the different blood types. Write a sentence describing what is revealed by the graph.

Make a scatter diagram for the data. -The following table gives the total sales (revenue)and profits for 8 retailers. $\begin{array}{lcc}\hline \text { Company } & \begin{array}{c}\text { Total Sales } \\\text { (Millions of \$) }\end{array} & \begin{array}{c}\text { Profits } \\\text { (Millions of \$) }\end{array} \\\hline \text { Adams } & 9.5 & 0.5 \\\text { Browns } & 22.0 & 1.4 \\\text { Clay } & 35.0 & 1.8 \\\text { Donners } & 64.0 & 3.0 \\\text { Esters } & 27.5 & 0.9 \\\text { Framer } & 45.0 & 2.6 \\\text { Gillies } & 15.0 & 0.8 \\\text { Hays } & 57.0 & 2.2 \\\hline\end{array}$

Use the graph to answer the question. - Mike decides to buy shares of companies X and Y, which were initially selling for the same price. The changes in the value of each stock over a 90-day period are shown in the graph above. Describe the trend in the value of each stock over the 90-day period.

Construct a pie chart representing the given data set. -Main form of exercise for employees of one company: None: 28\% Walking: 19\% Running: 6\% Golf: 11\% Weight Training: 25\% Other: 11\%

Provide an appropriate response. -Suppose that you construct a frequency histogram and a relative frequency histogram corresponding to a particular frequency table. In what ways will the two histograms be similar? In what ways will they differ?

Answer the question. -Which of the following describes the bias that can occur when members of a study's sample are volunteers?

Use the graph to answer the question. - In what quarter was the revenue the greatest for 1999?

Use the indicated bin size to construct a frequency table for the set of data. Include columns for relative frequency andcumulative frequency. -Kevin asked some of his friends how many hours they had studied for the test. The times are shown below: 5 6 5 4 5 5 9 7 5 3 7 6 6 7 5 6 7 5 6 7 6 7 7 4 Use 2-point bins $( 3 - 4,5 - 6$ , etc)

Construct a pie chart representing the given data set. - Favorite Pizza Topping Number of Responses Black olives 180 Mushrooms 150 Onions 70 Pepperoni 390

A sample statistic and margin of error are given. Find the confidence interval likely to contain the population parameterof interest and answer the question. -Ten years ago, according to government records, 17% of the population of Elmwood had no health insurance. This year a poll revealed that 20.6% were without insurance. The margin of error was 2.8 percentage points. Find a confidence interval for the true percentage without insurance this Year. Can we conclude that the percentage without insurance has increased from ten years ago?