Comp Sci unit 3 #2

Participants in a survey were asked how many hours per day they spend reading, how many hours per day they spend using a smartphone, and whether or not they would be interested in a smartphone application that lets users share book reviews.

The data from the survey are represented in the graph below. Each  represents a survey participant who said he or she was interested in the  application, and each  represents a participant who said he or she was not interested.

Which of the following hypotheses is most consistent with the data in the graph?

• Participants who read more were generally more likely to say they are interested in the application.

• Participants who read more were generally less likely to say they are interested in the application.

• Participants who use a smartphone more were generally more likely to say they read more.

• Participants who use a smartphone more were generally less likely to say they read more.

Grades in a computer science course are based on total points earned on a midterm exam and a final exam. The teacher provides a way for students to improve their course grades if they receive high scores on the final exam: if a student’s final exam score is greater than the student’s midterm exam score, the final exam score replaces the midterm exam score in the calculation of total points.

The table below shows two students’ scores on the midterm and final exams and the calculated total points each student earns.

• Khalil does better on the midterm exam than on the final exam, so his original midterm and final exam scores are added to compute his total points.

• Josefina does better on the final exam than on the midterm exam, so her final exam score replaces her midterm exam score in the total points calculation.

The teacher has data representing the scores of thousands of students. For each student, the data contain the student name, the midterm exam score, the final exam score, and the result of the total points calculation. Which of the following could be determined from the data?

I. The average total points earned per student
II. The average increase in total points per student as a result of the score replacement policy
III. The proportion of students who improved their total points as a result of the score replacement policy

• III only

• I and II only

• I and III only

• I, II, and III

A database of information about shows at a concert venue contains the following information.

• -Name of artist performing at the show

• -Date of show

• -Total dollar amount of all tickets sold

Which of the following additional pieces of information would be most useful in determining the artist with the greatest attendance during a particular month?

• Average ticket price

• Length of the show in minutes

• Start time of the show

• Total dollar amount of food and drinks sold during the show

A large data set contains information about all students majoring in computer science in colleges across the United States. The data set contains the following information about each student.

• -The student’s gender

• -The state in which the student attends college

• -The student’s grade point average on a 4.0 scale

Which of the following questions could be answered by analyzing only information in the data set?

• Do students majoring in computer science tend to have higher grade point averages than students majoring in other subjects?

• How many states have a higher percentage of female computer science majors than male computer science majors attending college in that state?

• What percent of students attending college in a certain state are majoring in computer science?

• Which college has the highest number of students majoring in computer science?

Historically, it has been observed that computer processing speeds tend to double every two years. Which of the following best describes how technology companies can use this observation for planning purposes?

• Technology companies can accurately predict the dates when new computing innovations will be available to use.

• Technology companies can plan to double the costs of new products each time advances in processing speed occur.

• Technology companies can set research and development goals based on anticipated processing speeds.

• Technology companies can spend less effort developing new processors because processing speed will always improve at the observed rate.

A retailer that sells footwear maintains a single database containing records with the following information about each item for sale in the retailer’s store.

• -Item identification number

• -Footwear type (sneakers, boots, sandals, etc.)

• -Selling price (in dollars)

• -Size

• -Color

• -Quantity available

Using only the database, which of the following can be determined?

• Which items listed in the database are not currently in the store

• Which colors are more popular among men than women

• Which type of footwear is most popular among adults

• The total number of shoes sold in a particular month

Each student at a school has a unique student ID number. A teacher has the following spreadsheets available.

• -Spreadsheet I contains information on all students at the school. For each entry in this spreadsheet, the student name, the student ID, and the student’s grade point average are included.

• -Spreadsheet II contains information on only students who play at least one sport. For each entry in this spreadsheet, the student ID and the names of the sports the student plays are included.

• -Spreadsheet III contains information on only students whose grade point average is greater than 3.5. For each entry in this spreadsheet, the student name and the student ID are included.

• -Spreadsheet IV contains information on only students who play more than one sport. For each entry in this spreadsheet, the student name and the student ID are included.

The teacher wants to determine whether students who play a sport are more or less likely to have higher grade point averages than students who do not play any sports. Which of the following pairs of spreadsheets can be combined and analyzed to determine the desired information?

• Spreadsheets I and II

• Spreadsheets I and IV

• Spreadsheets II and III

• Spreadsheets III and IV

A certain social media Web site allows users to post messages and to comment on other messages that have been posted. When a user posts a message, the message itself is considered data. In addition to the data, the site stores the following metadata.

• -The time the message was posted

• -The name of the user who posted the message

• -The names of any users who comment on the message and the times the comments were made

For which of the following goals would it be more useful to analyze the data instead of the metadata?

• To determine the users who post messages most frequently

• To determine the time of day that the site is most active

• To determine the topics that many users are posting about

• To determine which posts from a particular user have received the greatest number of comments

A file storage application allows users to save their files on cloud servers. A group of researchers gathered user data for the first eight years of the application’s existence. Some of the data are summarized in the following graphs. The line graph on the left shows the number of registered users each year. The line graph on the right shows the total amount of data stored by all users each year. The circle graph shows the distribution of file sizes currently stored by all users.

(note: 1 MB = 1,000 KB)

Which of the following observations is most consistent with the information in the circle graph?

• Over 75% of the files stored are 1 MB in size or less.

• Over 75% of the files stored are 10 MB in size or less.

• Over 75% of the files stored are at least 100 KB in size.

• Over 75% of the files stored are at least 1 MB in size.

Two different schools maintain data sets about their currently enrolled students. No individual student is enrolled at both schools. Each line of data contains information, separated by commas, about one student.

The two schools would like to combine their data to make a single data set. Which of the following can be done with the combined data?

Select two answers.

• The schools can create a single list of student names, sorted by last name.

• The schools can determine the average number of days students are absent.

• The schools can determine which ZIP code is represented by the most students.

• The schools can determine the student ID of the student with the greatest number of absences.