Data Science Missed Questions

A team of researchers wants to create a program to analyze the amount of pollution reported in roughly 3,000 counties across the United States. The program is intended to combine county data sets and then process the data. Which of the following is most likely to be a challenge in creating the program?

• The number of counties is too large for the program to process.

• The total number of rows of data is too large for the program to process.

• A computer program cannot combine data from different files.

• Different counties may organize data in different ways.

A code segment is intended to transform the list utensils so that the last element of the list is moved to the beginning of the list.

For example, if utensils initially contains ["fork", "spoon", "tongs", "spatula", "whisk"], it should contain ["whisk", "fork", "spoon", "tongs", "spatula"] after executing the code segment.

Which of the following code segments transforms the list as intended?

• len ←

  LENGTH(utensils)

  temp ←

  utensils[len]

  REMOVE(utensils, len)

  APPEND(utensils, temp)

• len ←

  LENGTH(utensils)

  temp ←

  utensils[len]

  REMOVE(utensils, len)

  INSERT(utensils, 1, temp)

• len ←

  LENGTH(utensils)

  REMOVE(utensils, len)

  temp ←

  utensils[len]

  APPEND(utensils, temp)

• len ←

  LENGTH(utensils)

  REMOVE(utensils, len)

  temp ←

  utensils[len]

  INSERT(utensils, 1, temp)

A search engine has a trend-tracking feature that provides information on how popular a search term is. The data can be filtered by geographic region, date, and category. Categories include arts and entertainment, computers and electronics, games, news, people and society, shopping, sports, and travel. Which of the following questions is LEAST likely to be answerable using the trends feature?

• What is the cost of a certain electronics product?

• In which political candidates are people interested?

• Which region of the country has the greatest number of people searching for opera performances?

• In what month does a particular sport receive the most searches?

A social media site allows users to send messages to each other. A group of researchers gathered user data for the first 10 years of the site’s existence. Some of the data are summarized in the table below, along with some of the company milestones.

The researchers noticed that the total number of registered users appears to be increasing at about a constant rate. If this pattern continues, which of the following best approximates the total number of registered users, in millions, in year 12 (two years after the last entry in the table) ?

• 32.4

• 30.6

• 31.8

• 31.2

The table below shows the time a computer system takes to complete a specified task on the customer data of different-sized companies.

Based on the information in the table, which of the following tasks is likely to take the longest amount of time when scaled up for a very large company of approximately 100,000 customers?

• Sorting data

• Searching through data

• Deleting entries from data

• Backing up data

Suppose a large group of people in a room were all born in the same year. Consider the following three algorithms, which are each intended to identify the people in the room who have the earliest birthday based on just the month and day. For example, a person born on February 10 is considered to have an earlier birthday than a person born on March 5. Which of the three algorithms will identify the correct people?

1) All the people in the room stand up. All standing people form pairs where possible, leaving at most one person not part of a pair. For each pair, the person with the earlier birthday remains standing, while the other person in the pair sits down. If there is a tie, both people sit down. Any individual not part of a pair remains standing. Continue doing this until only one person remains standing. That person has the earliest birthday.

2) All the people in the room stand up. All standing people form pairs with another standing person that they have not previously been paired with where possible, leaving at most one person not part of a pair. For each pair, the person with the earlier birthday remains standing, while the other person in the pair sits down. If there is a tie, both people in the pair remain standing. Any individual not part of a pair remains standing. Continue doing this until only one person remains standing or all persons standing have the same birthday. Anyone still standing has the earliest birthday.

3) Beginning with the number 1, ask if anyone was born on that day of any month. Continue with the numbers 2, 3, and so on until a positive response is received. If only one person responds, that person has the earliest birthday. If more than one person responds, determine which person was born in the earliest month, and that person or those persons have the earliest birthday.

• 1 only

• 2 only

• 1 and 2

• 2 and 3

Which of the following algorithms display all integers between 1 and 20, inclusive, that are not divisible by 3 ?

Select two answers.

• Step 1:

  Set x to 0.

   Step 2:

  Increment x by 1.

   Step 3:

  If x is not divisible by 3, then display x.

   Step 4:

  Repeat steps 2 and 3 until x is 20.

• Step 1:

  Set x to 1.

    Step 2: If x is divisible by 3, then do nothing; otherwise display x.Step 3:

  Increment x by 1.

    Step 4: Repeat steps 2 and 3 until x is greater than 20.

• Step 1:

  Set x to 1.

      Step 2: If x is divisible by 3, then do nothing; otherwise display x.Step 3:

  Increment x by 1.

    Step 4: Repeat steps 2 and 3 until x is 20.

• Step 1:

  Set x to 0.

  Step 2: If x is divisible by 3, then display x.Step 3:

  Increment x by 1.

   Step 4: Repeat steps 2 and 3 until x is greater than 20.

Consider a game in which a player flips a fair coin three times. If all three coin flips have the same result (either all heads or all tails) the player wins. Otherwise, the player loses.

Which of the following code segments best simulates the behavior of the game?

• 
• 
• 
• 

Consider the following code segment.

Which of the following CANNOT be displayed as a result of executing the code segment?

• 1 2 3 4

• 1 1 1 1

• 1 2 3 2

• 1 3 2 4

An application program interface (API) provides a procedure Max, which returns the greater of its two integer arguments.

A programmer would like to find the greatest of three integer values a, b, and c. Which of the following expressions will produce the desired result in every case?

• 
• 
• 
•