PS2310 Statistics for Social Science Chapter 2

2.1.5 a. Explain the difference between a discrete variable and a continuous variable. Choose the correct answer below. b. Give an example of each type. Choose the correct answer below.

A. A discrete variable has possible values that are separate​ numbers, while a continuous variable has possible values that form an interval. B. The number of children in a family is a discrete​ variable, while the time it takes to run a marathon is a continuous variable.

Part 2 of 3 b. Identify the modal category. Choose the correct answer below.

( the one with the most frequency is the answer ) Region D

Question 2.1.9 Part 1 or 3 Assume that 62 fatal shark attacks were recorded in a large body of water over a 9 year​ span, with 1 being reported in Region​ A, 2 in Region​ B, 4 in Region​ C, 20 in Region​ D, 13 in Region​ E, 6 in Region​ F, 3 in Region G and 5 in Region H. The rest occurred in other regions. Complete parts a through c below.

Construct the frequency table for the regions of the reported fatal shark attacks. ​(Type integers or decimals rounded to one decimal place as​ needed.) Region Frequency Percentage​ (%) A. 1, 1.6 B. 2, 3.2 C. 4, 6.5 D. 20, 32.3 E. 13, 21.0 F. 6, 9.7 G. 3, 4.8 H. 5, 8.1 Other. 8, 12.9 Total 62 100

Identify each of the following variables as continuous or discrete. a. The result of a roll of dice b. The characters typed per minute c. The decibel level of a siren d. Blood sugar level

a. The result of a roll of dice is a discrete variable since it has a finite number of possible values. b. The characters typed per minute is a discrete variable since it has a finite number of possible values. c. The decibel level of a siren is a continuous variable since it has an infinite continuum of possible values. d. Blood sugar level is a continuous variable since it has an infinite continuum of possible values.

Part 3 of 3 c. Describe the distribution of fatal shark attacks across the regions. Choose the correct answer below.

B. Region D and Region E are the single regions with the highest number of fatal shark attacks.

For 226 alligators captured in four different​ lakes, researchers classified the primary food choice​ (in volume) found in the​ alligator's stomach in one of the categories​ - fish,​ invertebrate, reptile,​ bird, or other. Use the bar chart to answer the following questions.

Is primary food choice categorical or​ quantitative? Categorical What is the modal category for primary food​ source? Invertebrate BirdBird Fish x Reptile Other About what percentage of alligators had reptilereptile as the primary food​ choice? 45​% X 40​% 38​% This type of bar​ chart, with categories listed in order of​ frequency, has a special name. What is​ it? Pareto

Identify each of the following variables as categorical or quantitative. a. College major b. Distance of commute to work c. Lucky day of the week d. Size of home Is the variable categorical or​ quantitative? Why?

a. College major is a categorical variable. Its values are not numerical. b.Distance of commute to work is a quantitative variable. Its values are numerical. c. Lucky Day of the week is a categorical variable. Its values are not numerical. d. Size of the home is a quantitative variable. Its values are numerical.

Identify each of the following variables as categorical or quantitative. a. Number of artificial flavors in a cereal b. Amount one paid on taxes c. Dream vacation location d. Clothing style Is the variable categorical or​ quantitative? Why?

a. Number of artificial flavors in a cereal is a quantitative variable. Its values are numerical. b. Amount one paid on taxes is a quantitative variable. Its values are numerical. c. Dream vacation location is a categorical variable. Its values are not numerical. d. Clothing style is a categorical variable. Its values are not numerical.

Question 2.2.10 In a certain​ year, most electricity was generated from coal ​(39​%), natural gas ​(31​%), or nuclear power plants ​(20​%). Hydropower accounted for 55​% of the total electricity​ produced; other renewable sources such as wind or solar power accounted for 33​%. Other nonrenewable sources​ (such as​ petroleum) made up the remaining 22​%. Complete parts a through d below. a. Display the information in a bar graph. The​ bars, from left to​ right, represent​ coal, natural​ gas, nuclear​ power, hydropower, wind or​ solar, and other nonrenewable sources. Choose the correct graph below. b. What is the advantage of using a graph to summarize the results instead of merely stating the percentages for each​ source? c. What is the advantage of using a graph to summarize the results instead of merely stating the percentages for each​ source? d. Which is the modal​ category

a. pick the right graph b. A bar chart is easier because sketching the exact percentages is more challenging in a pie chart c. A graph allows the viewer to more easily judge the relative sizes of the percentages in each category.

a. Explain the difference between categorical and quantitative variables. b. Give an example of a categorcal variable. c. Give an example of a quantitative variable.

A. A variable is called categorical if each observation belongs to one of a set of categories. A variable is called quantitative if observations on it take numerical values that represent different magnitudes of the variable. B. Dating Status, Gender