CH 2 HW
How do college professors spend their time? The National Education Association Almanac of Higher Education gives the following average distribution of professional time allocation: teaching, 49%; research, 14%; professional growth, 7%; community service, 11%; service to the college, 11%; and consulting outside the college, 8%. Make a pie chart showing the allocation of professional time for college professors.
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How does average height for boys change as boys get older? According to Physician's Handbook, the average heights at different ages are in the table below.
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Your friend is thinking about buying shares of stock in a company. You have been tracking the closing prices of the stock shares for the past 90 trading days. Which type of graph for the data, histogram or time-series, would be best to show your friend? Why?
A time-series graph because the pattern of stock prices over time is more relevant than the frequency of a range of closing prices.
A data set has values ranging from a low of 10 to a high of 52. What's wrong with using the class limits 10-19, 20-29, 30-39, 40-49 for a frequency table?
Each data value must fall into one class. The data values of 50 and above do not have a class.
A personnel office is gathering data regarding working conditions. Employees are given a list of five conditions that they might want to see improved. They are asked to select the one item that is most critical to them. Which type of graph, circle graph or Pareto chart, would be the most useful for displaying the results of the survey? Why?
Pareto chart, because it shows the items in order of importance to employees.
A data set has values ranging from a low of 10 to a high of 50. The class width is to be 10. What's wrong with using the class limits 10-20, 21-31, 32-42, 43-53 for a frequency table with a class width of 10?
The classes listed have a class width of 11.
A data set has values ranging from a low of 10 to a high of 50. What's wrong with using the class limits 10-20, 20-30, 30-40, 40-50 for a frequency table?
The classes overlap so that some data values, such as 20, fall within two classes.
In the Aloha state, you are very unlikely to be murdered! However, it is considerably more likely that your house might be burgled, your car might be stolen, or you might be punched in the nose. That said, Hawaii is still a great place for a vacation or, if you are very lucky, to live. The following numbers represent the crime rates per 100,000 population in Hawaii: murder, 4.6; rape, 38.4; robbery, 89.3; house burglary, 902.6; motor vehicle theft, 589.7; assault, 100.3. (a) Display this information in a Pareto chart, showing the crime rate for each category. (b) Could the information as reported be displayed as a circle graph? Explain. Hint: Other forms of crime, such as arson, are not included in the information. In addition, some crimes might occur together.
(a) -- (b) Yes, but the graph would take into account only these particular crimes and would not indicate if multiple crimes occurred during the same incident.
Certain kinds of tumors tend to recur. The following data represent the lengths of time, in months, for a tumor to recur after chemotherapy (Reference: D.P. Byar, Journal of Urology, Vol. 10, pp. 556-561). 19, 18, 17, 1, 21, 22, 54, 46, 25, 49, 50, 1, 59, 39, 43, 39, 5, 9, 38, 18, 14, 45, 54, 59, 46, 50, 29, 12, 19, 36, 38, 40, 43, 41, 10, 50, 41, 25, 19, 39, 27, 20 For this problem, use five classes. (a) Find the class width. (b) Make a frequency table showing class limits, class boundaries, midpoints, frequencies, relative frequencies, and cumulative frequencies. (Round your relative frequencies to two decimal places.) (c) Draw a histogram. (d) Draw a relative-frequency histogram. (e) Categorize the basic distribution shape. (f) Draw an ogive. (Graph each point and the closed line segments connecting the points to create your graph. This cannot be done in SALT.)
(a) 12 (b) class limits 1 - 12 13 - 24 25 - 36 37 - 48 49- 60 class boundaries 0.5 - 12.5 12.5 - 24.5 24.5 - 36.5 36.5 - 48.5 48.5 - 60.5 midpoint 6.5 18.5 30.5 42.5 54.5 frequency 6 10 5 13 8 relative frequency 0.14 0.24 0.12 0.31 0.19 cumulative frequency 6 16 21 34 42 (c) -- (d) -- (e) bimodal (f) --
How long did real cowboys live? One answer may be found in the book The Last Cowboys by Connie Brooks (University of New Mexico Press). This delightful book presents a thoughtful sociological study of cowboys in West Texas and Southeastern New Mexico around the year 1890. A sample of 32 cowboys gave the following years of longevity: 58, 52, 68, 86, 72, 66, 97, 89, 84, 91, 91, 92, 66, 68, 87, 86, 73, 61, 70, 75, 72, 73, 85, 84, 90, 57, 77, 76, 84, 93. 58, 47 (a) Make a stem-and-leaf display for these data. (Use the tens digit as the stem and the ones digit as the leaf. Enter numbers from smallest to largest separated by spaces. Enter NONE for stems with no values.) (b) Consider the following quote from Baron von Richthofen in his Cattle Raising on the Plains of North America: "Cowboys are to be found among the sons of the best families. The truth is probably that most were not a drunken, gambling lot, quick to draw and fire their pistols." Does the data distribution of longevity lend credence to this quote?
(a) Longevity of Cowboys 4 | 7 5 | 2 7 8 8 6 | 1 6 6 8 8 7 | 0 2 2 3 3 5 6 7 8 | 4 4 4 5 6 6 7 9 9 | 0 1 1 2 3 7 (b) Yes, these cowboys certainly lived long lives, as evidenced by the high frequency of leaves for stems 7, 8, and 9 (i.e., 70-, 80-, and 90-year-olds).
An annual marathon covers a route that has a distance of approximately 26 miles. Winning times for this marathon are all over 2 hours. The following data are the minutes over 2 hours for the winning male runners over two periods of 20 years each. Earlier Period 22, 13, 15, 12, 7, 12, 19, 15, 13, 23, 22, 18, 13, 8, 20, 14, 10, 18, 19, 15 Recent Period 9, 9, 7, 9, 8, 14, 9, 10, 8, 10, 9, 8, 9, 8, 14, 7, 7, 7, 9, 11 (a) Make a stem-and-leaf display for the minutes over 2 hours of the winning times for the earlier period. Use two lines per stem. (Use the tens digit as the stem and the ones digit as the leaf. Enter NONE in any unused answer blanks. For more details, view How to Split a Stem.) (b) Make a stem-and-leaf display for the minutes over 2 hours of the winning times for the recent period. Use two lines per stem. (Use the tens digit as the stem and the ones digit as the leaf. Enter NONE in any unused answer blanks.) (c) Compare the two distributions. How many times under 15 minutes are in each distribution? earlier period ___ times recent period ___ times
(a) Minutes Beyond 2 Hours, Earlier Period 0 | NONE 0 | 7 8 1 | 0 2 2 3 3 3 4 2 | 5 5 5 8 8 9 9 3 | 0 2 2 3 4 | NONE (b) Minutes Beyond 2 Hours, Recent Period 0 | NONE 0 | 7 7 7 7 8 8 8 8 9 9 9 9 9 9 9 1 | 0 0 1 4 4 1 | NONE (c) earlier period 9 times recent period 20 times
The book The Wall Street Journal. Guide to Information Graphics by Dona M. Wong gives strategies for using graphs and charts to display information effectively. One popular graph discussed is the donut pie chart. The donut pie chart is simply a pie chart with the center removed. A recent Harris Poll asked adults about their opinions regarding whether books should be banned from libraries because of social, language, violent, sexual, or religious content. The responses by education level to the question "Do you think that there are any books which should be banned completely?" are shown in the following donut pie charts. (a) What feature of Keith's graph makes it difficult to visually compare the responses of those with some college to those shown in the other graphs? (Select all that apply.) How would you change Keith's graph for easier comparison? (Select all that apply.) (b) Compare graphs made by Ramon. At which of the two education levels is the "no" response more frequent?
(a) The graphs do not have data labels showing the percentages. The donut hole in the graph made by Keith is a different size than in the graphs made by Ramon. Make all donuts exactly the same size, with the radius of the holes the same as well. Add data labels showing the percentages. (b) College graduate
It is costly in both time and money to go to college. Does it pay off? According to the Bureau of the Census, the answer is yes. The average annual income (in thousands of dollars) of a household headed by a person with the stated education level is as follows: 24.7 if ninth grade is the highest level achieved, 41.5 for high school graduates, 59.1 for those holding associate degrees, 82.5 for those with bachelor's degrees, 100.8 for those with master's degrees, and 121.4 for those with doctoral degrees. Make a bar graph showing household income for each education level.
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It's not an easy life, but it's a good life! Suppose you decide to take the summer off and sign on as a deck hand for a commercial fishing boat in Alaska that specializes in deep-water fishing for groundfish. What kind of fish can you expect to catch? One way to answer this question is to examine government reports on groundfish caught in the Gulf of Alaska. The following list indicates the types of fish caught annually in thousands of metric tons: flatfish, 36.0; Pacific cod, 67.8; sablefish, 16.0; Walleye pollock, 71.5; rockfish, 20.6. Make a Pareto chart showing the annual harvest for commercial fishing in the Gulf of Alaska.
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A data set with whole numbers has a low value of 20 and a high value of 96. Find the class width for a frequency table with seven classes. Find the class limits for a frequency table with seven classes.
11 20 - 30 31 - 41 42 - 52 53 - 63 64 - 74 75 - 85 86 - 96