10+ TCS Interview Questions and Answers

Descriptive statistics summarize data, while inferential statistics make predictions or inferences about a population based on a sample.

• Descriptive statistics describe the main features of a dataset, such as mean, median, and standard deviation.

• Inferential statistics involve making predictions or inferences about a population based on a sample, using techniques like hypothesis testing and confidence intervals.

• Example: Descriptive statistics would be calculating the average he...read more

I am currently working on a project analyzing customer behavior in an e-commerce platform.

• Using regression analysis to identify factors influencing customer purchase decisions

• Applying clustering techniques to segment customers based on their behavior

• Utilizing hypothesis testing to determine the effectiveness of marketing strategies

Degree of freedom represents the number of independent values or quantities which can be assigned to a statistical distribution.

• Degree of freedom is the number of values in the final calculation of a statistic that are free to vary.

• In simple terms, it signifies the number of independent pieces of information available to estimate a parameter.

• For example, in a t-test, the degree of freedom is n-1, where n is the sample size.

• In ANOVA, the degree of freedom for between groups is...read more

T-test is a statistical test used to determine if there is a significant difference between the means of two groups.

• T-test is used to compare the means of two groups to see if they are significantly different.

• Assumptions for t-test include normal distribution of data, independence of observations, and homogeneity of variances.

• There are two types of t-tests: independent samples t-test and paired samples t-test.

• T-distribution is similar to the normal distribution but with heavi...read more

EventLoop is a mechanism in JavaScript that allows for asynchronous execution of code.

• EventLoop is responsible for managing the execution of code in JavaScript.

• It ensures that code is executed in a non-blocking manner.

• EventLoop continuously checks for any pending tasks and executes them.

• It maintains a call stack and a task queue to manage the order of execution.

• EventLoop is crucial for handling asynchronous operations in JavaScript.

Clinical trials are research studies that test how well new medical treatments work in people.

• Clinical trials are conducted to evaluate the safety and efficacy of new treatments or interventions.

• There are typically four phases in clinical trials: Phase 1, Phase 2, Phase 3, and Phase 4.

• In Phase 1, the sample size is usually small (20-100 participants) to assess safety and dosage.

• Phase 2 involves a larger sample size (100-300 participants) to evaluate effectiveness and side eff...read more

P-value is a measure that helps determine the strength of evidence against the null hypothesis in statistical hypothesis testing.

• P-value is the probability of obtaining results as extreme as the observed results, assuming the null hypothesis is true.

• A low p-value (typically ≤ 0.05) indicates strong evidence against the null hypothesis, leading to its rejection.

• For example, if a study comparing two drugs shows a p-value of 0.03, it suggests that there is a 3% chance that the r...read more

ANOVA is used to compare means of three or more groups. Assumptions include normality, homogeneity of variances, and independence.

• ANOVA is used to compare means of three or more groups to determine if there is a significant difference among them.

• Assumptions for ANOVA include normality of data within each group, homogeneity of variances between groups, and independence of observations.

• Example: ANOVA can be used to compare the average test scores of students in different school...read more

Descriptive statistics techniques include measures of central tendency, dispersion, skewness, and kurtosis.

• Measures of central tendency include mean, median, and mode.

• Measures of dispersion include range, variance, and standard deviation.

• Skewness measures the asymmetry of the data distribution.

• Kurtosis measures the peakedness or flatness of the data distribution.

• The three types of kurtosis are mesokurtic (normal distribution), leptokurtic (tall and sharp peak), and platykurti...read more

Box plot is a visual representation of the distribution of a dataset, used to identify outliers and assess skewness.

• Box plot displays the median, quartiles, and potential outliers of a dataset.

• It is used to visually assess the spread, skewness, and presence of outliers in the data.

• Skewness can be assessed from the box plot by observing the relative lengths of the whiskers and the position of the median.

Heteroscedasticity is when the variability of a variable is unequal across the range of values of a second variable.

• Heteroscedasticity refers to the situation where the variance of errors or residuals is not constant across all levels of the independent variable.

• It violates the assumption of homoscedasticity in regression analysis.

• For example, in a scatter plot, if the spread of data points widens or narrows as the value of the independent variable increases, it indicates het...read more