YOU WERE LOOKING FOR: Probability Interview Questions And Answers
Cards of hearts and diamonds are red cards. There are 4 honours of each unit. There are Kings, Queens and Jacks. These are all called face cards. Sample Space: When we perform an experiment, then the set S of all possible outcomes is called the...
This is a contradiction. This is again a contradiction. So none of the provided answer choices are correct. Behind one is a expensive car, but behind the other two are goats. After you have chosen one door, he reveals one of the other two doors...
View Answer Discuss Henry should have Gretchen pull the trigger again without spinning. We know that the first chamber Gretchen fired was one of the four empty chambers. Since the bullets were placed in consecutive order, one of the empty chambers is followed by a bullet, and the other three empty chambers are followed by another empty chamber.
What are the security implementations that are present in Node. Following are the important implementations for security: Error handling protocols Authentication pipelines What is the meaning of a test pyramid? A test pyramid is a methodology that is used to denote the number of test cases executed in unit testing, integration testing, and combined testing in that order. This is maintained to ensure that an ample number of test cases are executed for the end-to-end development of a project. Next up on these Node js interview questions, it is vital that you know about Libuv. Read on. What is libuv? Libuv is a widely used library present in Node. It was developed in-house and used alongside systems such as Luvit, Julia, and more.
Following are some of the features of libuv: File system event handling Asynchronous UDP and TCP sockets Asynchronous file handling and operations Next among the Node js questions, you need to understand a question about the functioning of Google Chrome. Why does Google use the V8 engine for Node. Google makes use of the V8 engine because it can easily convert JavaScript into a low-level language. This is done to provide high performance during the execution of an application and also to provide users with real-time abilities to work with the application. What is the difference between spawn and fork methods in Node.
The spawn function is used to create a new process and launch it using the command line. What it does is that it creates a node module on the processor. Spawning ensures that there are more than one active worker node to handle tasks at any given point of time. What is the use of middleware in Node. A middleware is a simple function that has the ability to handle incoming requests and outbound response objects. Middleware is used primarily for the following tasks: Execution of code of any type Updation of request and response objects Completion of request—response iterations Calling the next middleware What are global objects in Node.
Global objects are objects with a scope that is accessible across all of the modules of the Node. There will not be any need to include the objects in every module. One of the objects is declared as global. So, this is done to provide any functions, strings, or objects access across the application. Next among the Node js coding questions you need to take a look at the usage of assets in Node js. Why is assert used in Node. Assert is used to explicitly write test cases to verify the working of a piece of code. What are stubs in Node. Stubs are simply functions that are used to assess and analyze individual component behavior. When running test cases, stubs are useful in providing the details of the functions executed. This is done using the following: A higher number of unit test cases A smaller number of integration test methods A fewer number of HTTP endpoint test cases Why is a buffer class used in Node. A buffer class is primarily used as a way to store data in Node.
This can be considered as a similar implementation of arrays or lists. Here, the class refers to a raw memory location that is not present in the V8 heap structure. The buffer class is global, thereby extending its usage across all the modules of an application. Why is ExpressJS used? ExpressJS is a widely used framework built using Node. Being lightweight and flexible, Express. What is the use of the connect module in Node.
The connect module in Node. This also provides easy integration with Express. What are streams in Node. Streams are a set of data entities in Node. These can be considered similar to the working of strings and array objects. But, if the channel is not available, then all of the data cannot be pushed to the memory at once. Hence, using streams will make it easy to process a large set of data in a continuous manner. Next up on this compilation of top node js interview questions for experienced, let us check out the advanced category of questions.
Advanced Interview Questions What are the types of streams available in Node. It provides users with a virtual environment to test JavaScript code in Node. After this, JavaScript commands can be typed directly into the command line. What is meant by tracing in Node. Tracing is a methodology used to collect all of the tracing information that gets generated by V8, the node core, and the userspace code. All of these are dumped into a log file and are very useful to validate and check the integrity of the information being passed. Where is package. It can also be used as a project identifier and deployed as a means to handle all of the project dependencies. What is the difference between readFile and createReadStream in Node. All of the content will be read into the memory before users can access it.
The default chunk size is 64 KB, and this can be changed as per requirement. What is the use of the crypto module in Node. The crypto module in Node. This provides them with a large number of wrappers to perform various operations such as cipher, decipher, signing, and hashing operations. What is a passport in Node. Passport is a widely used middleware present in Node. It is primarily used for authentication, and it can easily fit into any Express. With every application created, it will require unique authentication mechanisms. This is provided as single modules by using passport, and it becomes easy to assign strategies to applications based on requirements, thereby avoiding any sort of dependencies. How to get information about a file in Node.
The fs. The syntax is as follows: fs. How does the DNS lookup function work in Node. There are other parameters such as the options that are used to set the input as an integer or an object. If nothing is provided here, both IPv4 and IPv6 are considered. The third parameter is for the callback function.
The syntax is: dns. What is the use of EventEmitter in Node. Every single object in Node. These objects have a function that is used to allow the attachment between the objects and the named events. Synchronous attachments of the functions are done when the EventEmitter object emits an event. What is the difference between setImmediate and setTimeout? The setImmediate function is meant to execute a single script once the current event loop is complete. The setTimeout function is used to hold a script and schedule it to be run after a certain time threshold is over.
The order of execution will solely depend on the context in which the functions are called. If called from the main module, the timing will be based on the performance of the process. What is the use of module. The module. A module is an entity that is used to store relative code in a single snippet. This can be considered as an operation of moving all of the functions into one single file. Why do you think you are the right fit for this Node. Here, the interviewer wants to know your understanding of the job role and the company architecture and your knowledge on the topic.
While answering this question, it would add immensely if you knew the job description in detail and the basic usage of the technology in the company. The answer can be further elaborated with how your interests align with the technology, job, and the company. Do you have any past Node. This question is common among Node. This is used as a measure to see if you have had any hands-on experience with the language in a working environment before. Do you have any experience working in the same industry as ours?
Users who have contributed to this file 70 lines 66 sloc 6. What is the proba- bility that you see at least one shooting star in the period of an hour? Or, we can use Poisson processes 3. How can you generate a random number between 1 - 7 with only a die? Launch it 3 times: each throw sets the nth bit of the result. For each launch, if the value is , record a 0, else 1. The result is between 0 and 7 , evenly spread 3 independent throw. Repeat the throws if 0 was obtained: the process stops on evenly spread values. How can you get a fair coin toss if someone hands you a coin that is weighted to come up heads more often than tails? You have an mixture of two normal distributions with the same standard deviation. How far apart do the means need to be in order for this distribution to be bimodal? Given draws from a normal distribution with known parameters, how can you simulate draws from a uniform distribution? A certain couple tells you that they have two children, at least one of which is a girl.
What is the probability that they have two girls? You have a group of couples that decide to have children until they have their first girl, after which they stop having children. What is the expected gender ratio of the children that are born? What is the expected number of children each couple will have? Expected number of children is 2. How many ways can you split 12 people into 3 teams of 4? Your hash function assigns each object to a number between , each with equal probability. With 10 objects, what is the probability of a hash collision? What is the expected number of hash collisions? What is the expected number of hashes that are unused. If the time that each takes to reach you is IID, what is the probability that all the Lyfts arrive first? I write a program should print out all the numbers from 1 to , but prints out Fizz instead if the number is divisible by 3, Buzz instead if the number is divisible by 5, and FizzBuzz if the number is divisible by 3 and 5.
What is the total number of numbers that is either Fizzed, Buzzed, or FizzBuzzed? On a dating site, users can select 5 out of 24 adjectives to describe themselves. A match is declared between two users if they match on at least 4 adjectives. If Alice and Bob randomly pick adjectives, what is the probability that they form a match? A lazy high school senior types up application and envelopes to n different colleges, but puts the applications randomly into the envelopes. What is the expected number of applications that went to the right college?
On average, what would you expect the height of his son to be? Taller, equal, or shorter? What if you had a very short father? Regression to the mean HH is the final state. Solve linear equation:.
Since logistic regression is very easy to understand and implement, this algorithm is perfect for beginners and the people just starting their machine learning or data science journey. Although the name logistic regression might sound like the algorithm that one might use to implement regression, the truth is far from it. Logistic regression , because of its nuances, is more fit to actually classify instances into well-defined classes than actually perform regression tasks. In a nutshell, this algorithm takes linear regression output and applies an activation function before giving us the result. The activation function which logistic regression uses is that of sigmoid function also known as a logistic function.
After setting a threshold value, making classification from the output of logistic regression becomes a breeze. We all know how the field of data science and machine learning is evolving. More opportunities are being created daily. So, in this competitive cut-throat world, making sure you have the right knowledge is key to ensuring a good placement in the company of your dreams. To aid you in this endeavor of yours, we have prepared a list of logistic regression interview questions that should help you prepare for the journey to become a professional data scientist or a machine learning professional. Is logistic regression a type of a supervised machine learning algorithm? Yes, the answer to this question would be TRUE because, indeed, logistic regression is a supervised machine learning algorithm. The simple reason why lies in the way this algorithm works. To get output from logistic regression, you will have to feed it with data first.
You will have to provide the instances and the correct labeling of these instances for it to be able to learn from them and make accurate predictions. A supervised machine learning algorithm would need both a target variable Y and the class instances or the variable used to provide input information X to be able to train and make predictions successfully. Is logistic regression mainly used for classification? Yes, the answer to this question is TRUE. Indeed, logistic regression is primarily used for classification tasks rather than performing actual regression. We use linear regression for regression. Due to the similarity between the two, it is easy to get confused. Do not make this mistake. In logistic regression, we use the logistic function, which is nothing but a sigmoid activation function, which makes classification tasks much more comfortable. Can a neural network be implemented, which mimics the behavior of a logistic regression algorithm?
Yes, the answer would be TRUE. Neural networks are also known as universal approximators. They can be used to mimic almost any machine learning algorithm. Can we use logistic regression to solve a multi-class classification problem? The short answer would be TRUE. The long answer, however, would have you thinking a little. There is no way in which you can implement a multi-class classification from just using one single logistic regression model. You will need to either use a neural network with a softmax activation function or use a complex machine-learning algorithm to predict many classes of your input variable successfully. However, there is one way in which you can actually use the logistic regression to solve a multi-class classification problem. That would be by using a one vs.
You will need to train n classifiers where n is the number of classes , each of them predicting just one class. So, in a case of three-class classification let us say A, B, and C , you will need to train two classifiers one to predict A and not A, another one to predict B and not B, and the final classifier predicting C and not C. Then you will have to take the outputs from all these three models integrate them together to be able to do a multi-class classification using nothing but logistic regression.
Choose one of the options from the list below. What is the underlying method which is used to fit the training data in the algorithm of logistic regression? Jaccard Distance Least Square error None of the options which are mentioned above. The answer is B. It is easy to select option C, which is the Least Square error because this is the same method that is used in linear regression. However, in logistic regression, we do not use the Least square approximation to fit the training instances into the model; we use Maximum Likelihood instead. Which metric would we not be able to use to measure the correctness of a logistic regression model?
The correct option you should choose is C, i. Since the logistic regression algorithm is actually a classification algorithm rather than a basic regression algorithm, we cannot use the Meas Square Error to determine the performance of the logistic regression model that we wrote. The main reason is because of the output that we receive from the model and the inability to assign a meaningful numeric value to a class instance. AIC happens to be an excellent metric to judge the performance of the logistic regression model. AIC is very similar to the R-squared method that is used to determine the performance of a linear regression algorithm.
What is actually true about this AIC? The model with a low AIC score is generally preferred. The model which has s huge AIC score is actually preferred. The choice of the model just from the basis of the AIC score highly depends on the situation. None of the options which are mentioned above. The model which has the least value of AIC is preferred. So, the answer to the question would be option A. The main reason why we choose the model with the lowest possible value of AIC is because the penalty, which is added to regulate the performance of the model, actually does not encourage the fit to be over. In practice, we prefer the models which are neither under fitted meaning it cannot generalize well because the model which we have chosen is not complex enough to find the intricacies present in the data nor overfitting meaning the model has fitted perfectly to the training data and it has lost the ability to make more general predictions. So, we choose a reasonably low score to avoid both under and overfitting.
Do we need to standardize the values present in the feature columns before we feed the data into a training logistic regression model? No, we do not need to standardize the values present in the feature space, which we have to use to train the logistic regression model. We choose to standardize all our values to help the function usually gradient descent , which is responsible for making the algorithm converge on a value.
Since this algorithm is relatively simple, it does not need the amounts to be scaled for it actually to have a significant difference in its performance. Which is the technique we use to perform the task of variable selection? The answer to this question is B. LASSO regression. The reason is simple, the l2 penalty, which is incurred in the LASSO regression function, has the ability to make the coefficient of some features to be zero. Since the coefficient is zero, meaning they will not have any effect in the final outcome of the function. This means these variables are not as important as we thought them to be, and in this way, with the help of LASSO regression, we can perform a variable selection. Assume that you have a fair coin in your possession with the aim to find out the odds of getting heads. What would be your calculated odds? Would the odds of getting head be 0 Would the odds of getting head be 1 Would the odds of getting head be 0. To successfully answer this question, you would need to understand the meaning and definition of odds.
Odds are actually defined as the ratio of two probabilities—the probability of happening to the likelihood of not happening of any particular event. In the case of any coin, which is fair, the possibility of head and probability of not heads are the same. So, the odds of getting heads is one. Choose the correct answer from the options below. The logit function is defined as the log of the odds function. What do you think the range of this logit function be in the domain of [0,1]? The probability function takes the value which it is passed with and turns it into a probability. Meaning the range of any function is clamped in between zero and one. However, the odds function does one thing it takes the value from the probability function and makes the range of it from zero to infinity. So, the effective input to the log function would be from zero to infinity. We know that the log function range in this domain Is the entire real number line or negative infinity to positive infinity.
So, the answer to this question is option A. Choose the option which you think is TRUE from the list below: The error values in the case of Linear regression have to follow a normal distribution, but in the case of logistic regression, the values do not have to follow a standard normal distribution. The error values in the case of Logistic regression have to follow a normal distribution, but in the case of Linear regression, the values do not have to follow a standard normal distribution.
The error values in the case of both Linear regression and Logistic regression has to follow a normal distribution. The error values in the case of both Linear regression and Logistic regression do not have to follow a normal distribution. The only truthful statement in the bunch of these statements is the first one. So, the answer to the question becomes the option A. Choose the correct option S from the list of options down below. So, let us say that you have applied the logistic regression model into any given data. The accuracy results that you got are X for the training set and Y for the test set. Now, you would like to add more data points to your model. So, what, according to you, should happen? The Accuracy X, which we got in the training data, should increase.
The Accuracy X, which we got from the training data, should decrease. The Accuracy Y, which we got from the test data, should decrease.
Data scientists need a deep understanding of the methods and uses of probability to complete the complex data study they perform in the workplace. You can use probability questions to practice solving real-world statistical problems before you interview for a job as a data scientist. In this article, we provide examples of the types of probability questions you may be asked to prove your knowledge of this mathematical concept when interviewing for a position in data science. General questions Interviews often begin or end with general questions. Here are some sample questions that an interviewer may ask you about generic topics as you apply for a position in data science: Why are you interested in this position? What made you choose this line of work? Can you tell me about a time you overcame a challenge? What do you do if you fail at a task?
No comments:
Post a Comment