Common Technical Interview Questions and Answers Update on October 30, 2021

Exam Question 51

Explain the difference between the terms correlation and covariance.

A. Covariance is the measure that indicates the extent to which two variables change in tandem, while correlation represents how strongly two random variables are related.
B. Covariance is when a change in one variable directly results in the change in another, while correlation is when two variables vary with each other.
C. Covariance and correlation are interchangeable terms regarding data.
Correct Answer:
A. Covariance is the measure that indicates the extent to which two variables change in tandem, while correlation represents how strongly two random variables are related.

Exam Question 52

Which of the following are types of join in SQL?

A. Inner, right, left and full join
B. Top, inner, left and right join
C. Right, left, full and empty join
D. Full, empty, inner and top join
Correct Answer:
A. Inner, right, left and full join

Exam Question 53

True or false: Cursor, clustered and nonclustered Index are the three types of indexes in SQL.

A. True
B. False – The three types of indexes are unique, clustered and nonclustered.
Correct Answer:
B. False – The three types of indexes are unique, clustered and nonclustered.

Exam Question 54

Which of these is not a valid strategy to combat overfitting in decision trees?

A. Employ cross-validation and divide your data set into test sets, training sets and hold out groups and train and test your model on the correct respective groups.
B. Adding more data can help algorithms detect signal better.
C. Embrace early stopping and cease training before new iterations lead to overfitting.
D. Increase the number of input features in order to combat overfitting.
Correct Answer:
D. Increase the number of input features in order to combat overfitting.

Exam Question 55

Which of these statements is untrue regarding the rise of deep learning in recent years?

A. The increased processing power emanating from GPUs has helped feed a growth in deep learning.
B. An explosion of available data has made deep learning more feasible.
C. The continued advancement of algorithms has reached the level where deep learning is more feasible.
D. There has not been a notable increase in organizational usage of deep learning.
Correct Answer:
D. There has not been a notable increase in organizational usage of deep learning.

Exam Question 56

True or false: In regard to the 80/20 rule, data scientists spend 80% of their time finding and organizing data and only 20% of their time performing analysis.

A. True
B. False
Correct Answer:
A. True

Exam Question 57

What makes ‘Naïve’ Bayes naïve?

A. Naïve Bayes assumes that each individual variable is independent of the others.
B. Naïve Bayes assumes that variables are dependent on one another.
C. Naïve Bayes can’t classify certain data sets.
D. As a predecessor to the Bayes’ Theorem, it is generally regarded as naïve.
Correct Answer:
A. Naïve Bayes assumes that each individual variable is independent of the others.

Exam Question 58

Which of the following is not a potential shadow IoT device?

A. Medical device
B. Drone
C. Smartphone
D. Wireless thumb drive
Correct Answer:
C. Smartphone
Answer Description:
Although smartphones can serve as a way to control IoT devices and applications, they are not considered IoT devices. Smartphones and PCs serve as general purpose devices, but IoT devices have dedicated functions such as measuring temperature. With the growing number of connected devices used in personal and work environments, shadow IoT has become a security risk that organizations must not ignore. Employees often connect devices, such as medical devices, drones or wireless thumb drives, to enterprise networks without approval. IT admins can’t monitor and protect connections unsanctioned for use if they don’t know about them.

Exam Question 59

_________ are physical devices or software programs that route inbound or outbound data between controllers, sensors and devices and the cloud or servers and provide an additional layer of security for IoT data while in transit.

A. IoT actuators
B. IoT portcullis
C. IoT sensors
D. IoT gateways
Correct Answer:
D. IoT gateways
Answer Description:
IoT gateways manage the transfer of IoT data and add an extra security layer because they only transmit authorized data. If an attacker hacks an IoT device, gateways block the data from the network.

Exam Question 60

What is the difference between IoT authentication and authorization?

A. Authentication is the process of device identification, and authorization provides permissions.
B. Authentication provides an undisputed connection, and authorization is the process of writing identification.
C. Authentication gives permissions to human users, but authorization gives permissions to devices.
D. Authentication is when technology confirms you are not a robot, and authorization is when an OS confirms your login information.
Correct Answer:
A. Authentication is the process of device identification, and authorization provides permissions.
Answer Description:
IT admins use device authentication and authorization as components of their cybersecurity strategy. Devices must be authenticated to determine that the device is what it declares it is by checking if its credentials match the credentials in a database or server of authorized users. Authorization gives IoT devices or users permission to do or have something. Both processes ensure IoT devices only have access and permission to do what they need to do.