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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.

1.

In a 15-minute interval, there is a 20% probability of seeing at least one shooting star. What is the proba­bility that you will see at least one shooting star in one hour?

Answer»

<P>The probability of not seeing ONE SHOOTING STAR in 15 minutes is
= 1 – P( One shooting star )
= 1 – 0.2 = 0.8 (20% probability, hence, 0.2)

The probability of not seeing any shooting star in an hour:
(0.8) ^ 4 = 0.4096

The probability of seeing one shooting star in an hour
= 1 – P( Not seeing any star )
= 1 – 0.4096 = 0.5904

Ans: 0.5904

2.

What do you understand by the Law of Large Numbers?

Answer»

The LAW of large NUMBERS, according to probability and statistics, STATES that as a sample size increases, the mean value gets closer to the AVERAGE of the total population size.

3.

What is the need for Re-sampling?

Answer»

Resampling is USED for:

  • The estimation of accuracy involving sample statistics by using multiple subsets of accessible DATA or by drawing from a SET of data POINTS randomly.
  • The SUBSTITUTION of labels on data points while performing the necessary tests.
  • The validation of models through the usage of random subsets such as bootstrapping or cross-validation.
4.

What is the primary goal of A/B Testing in Data Science?

Answer»

A/B Testing is a hypothesis testing used for a randomized experiment concerning two variables, A and B.

The primary goal of A/B Testing is identifying any changes on the web PAGE for maximizing or increasing the OUTCOME of interest. This is an EXCELLENT method for coming up with the best online promotions and other MARKETING strategies related to any business. It is used for multiple purposes such as website copy, digital ads, or EVEN sales emails.

5.

What do you understand by selection bias and mention its types?

Answer»

Selection BIAS is a type of error that crops up when the researcher is deciding who/what is going to be studied. It is usually associated with research whose selection of participants is not random.

It is sometimes also mentioned as the selection effect. It involves the distortion of statistical analysis, which is a result of the METHOD of collecting samples. It is vital to the WHOLE process as, without this, the conclusions may not be accurate.

Here are the TYPES of selection bias:
  • Sampling bias
  • Time interval Bias
  • Data Bias
  • Attrition Bias
6.

Mention the differences between supervised and unsupervised learning?

Answer»
Supervised LearningUnsupervised Learning
Here, the input data is labeled.Here, the input data is not labeled.
It USES a training data set.It uses the input data set.
It is primarily used for data prediction.It is primarily used for data analysis.
It helps in ENABLING REGRESSION and classification of data.It helps in enabling the density estimation, DIMENSION reduction, and classification of data.
7.

What do you essentially mean by data science?

Answer»

Data Science is a BLEND of VARIOUS fields using scientific processes, algorithms, and machine learning PRINCIPLES to extract information and insights from structural and unstructured FORMS of data.

It focuses on finding any hidden patterns from the raw data and turn it into a valuable resource for DEVELOPING businesses and IT strategies.