Statistical Analysis for Big Data Technologies in Data Science

Question 1

Which of the following is NOT a recognized type of statistical analysis?

Accepted Answer

Predictive statistics

Answer

Descriptive statistics

Answer

Inferential statistics

Question 2

What is the primary objective of descriptive statistics?

Accepted Answer

Summarize and describe data

Answer

Make inferences about a population

Answer

Test hypotheses

Answer

Predict future outcomes

Question 3

Which measure of central tendency is least affected by extreme values?

Accepted Answer

Median

Answer

Mean

Answer

Mode

Answer

Standard deviation

Question 4

Which of the following statistical tests does not assume normally distributed data?

Accepted Answer

Chi-square test

Answer

t-test

Answer

ANOVA

Answer

Regression analysis

Question 5

What is the central purpose of hypothesis testing in statistical analysis?

Accepted Answer

To assess whether observed data significantly differs from expected results

Answer

To estimate population parameters

Answer

To predict future outcomes

Answer

To summarize and describe data

Question 6

Which of the listed options is NOT a type of hypothesis test?

Accepted Answer

Linear regression

Answer

One-sample t-test

Answer

Two-sample t-test

Answer

Analysis of Variance (ANOVA)

Question 7

In the context of hypothesis testing, what is the interpretation of the critical value?

Accepted Answer

The boundary value that divides rejection and acceptance regions

Answer

The probability of rejecting the null hypothesis

Answer

The difference between observed and expected values

Answer

The significance level of the test

Question 8

Which of the following actions is NOT part of the statistical analysis process?

Accepted Answer

Model training

Answer

Data collection

Answer

Data cleaning and preparation

Answer

Data interpretation

Question 9

What statistical measure is commonly used to describe the central tendency of a data set?

Accepted Answer

Mean

Answer

Standard deviation

Answer

Variance

Answer

Correlation coefficient

Question 10

What is the primary purpose of a hypothesis test?

Accepted Answer

To determine if there is a statistically significant difference between two or more data sets

Answer

To predict the future value of a variable

Answer

To describe the distribution of a data set

Answer

To generate a random sample

Question 11

Which statistical test is commonly used to compare the means of two independent data sets?

Accepted Answer

T-test

Answer

ANOVA

Answer

Chi-square test

Answer

Regression analysis

Question 12

What is the primary role of Apache Hadoop in Big Data processing?

Accepted Answer

It provides a framework for storing and processing large data sets in a distributed environment.

Answer

It is a programming language specifically designed for Big Data analysis.

Answer

It is a cloud computing platform that provides managed services for Big Data processing.

Answer

It is a tool for data visualization and exploration.

Question 13

What is the primary purpose of data visualization?

Accepted Answer

To effectively communicate data insights

Answer

To store and manage large data sets

Answer

To perform statistical analysis

Answer

To train machine learning models

Question 14

Which measure of central tendency is least affected by outliers?

Accepted Answer

Median

Answer

Mean

Answer

Mode

Question 15

The coefficient of variation measures:

Accepted Answer

Relative dispersion

Answer

Central tendency

Answer

Skewness

Question 16

Approximately what percentage of data in a normal distribution falls within one standard deviation of the mean?

Accepted Answer

68%

Answer

50%

Answer

95%

Question 17

Which statistical test is used to compare the means of two independent groups?

Accepted Answer

Independent t-test

Answer

ANOVA

Answer

Paired t-test

Question 18

What is the main principle of hypothesis testing?

Accepted Answer

Rejecting the null hypothesis only when the evidence strongly supports the alternative hypothesis

Answer

Accepting the null hypothesis even when the evidence weakly supports the alternative hypothesis

Answer

Always accepting the alternative hypothesis

Question 19

Which of the following is an advantage of utilizing statistical analysis in data science?

Accepted Answer

Making data-driven decisions

Answer

Eliminating the need for data collection

Answer

Guaranteeing accurate predictions

Answer

Replacing the need for human expertise

Question 20

What is the key distinction between a sampling error and a non-sampling error?

Accepted Answer

Sampling errors are random variations, while non-sampling errors are systematic biases

Answer

Non-sampling errors are always more severe than sampling errors

Answer

Sampling errors are larger than non-sampling errors

Answer

Sampling errors can be eliminated by increasing the sample size

Question 21

What is the primary purpose of data visualization in statistical analysis?

Accepted Answer

Effectively communicating statistical results and insights

Answer

Replacing the need for statistical analysis

Answer

Improving the accuracy of statistical calculations

Answer

Ensuring that statistical results are unbiased

Question 22

Which practice is recommended for communicating statistical results?

Accepted Answer

Using clear and simple language, avoiding technical jargon

Answer

Presenting only the most statistically significant results

Answer

Ignoring results that do not align with the desired conclusion

Answer

Exaggerating the implications of the results to make them more impactful

Question 23

Which of the following is NOT a measure of central tendency?

Accepted Answer

Variance

Answer

Mode

Answer

Mean

Answer

Median

Question 24

A probability distribution of a discrete random variable is defined as:

Accepted Answer

A function that assigns a probability to each possible outcome.

Answer

A graphical representation of the possible outcomes.

Answer

A table that shows the frequency of each outcome.

Question 25

In the context of hypothesis testing, the level of significance (α) represents:

Accepted Answer

The probability of rejecting the null hypothesis when it is true (Type I Error).

Answer

The probability of accepting the null hypothesis when it is false.

Answer

The probability of making a Type II error.

Question 26

Which of the following statistical tests is non-parametric?

Accepted Answer

Chi-square test

Answer

ANOVA

Answer

Regression analysis

Answer

t-test

Question 27

Multiple regression analysis is primarily used to:

Accepted Answer

Predict a continuous dependent variable using multiple independent variables.

Answer

Predict a categorical dependent variable using a single independent variable.

Answer

Test the significance of a single independent variable.

Question 28

In the context of a multiple regression model, the R-squared value represents:

Accepted Answer

The proportion of variance in the dependent variable explained by the independent variables.

Answer

The number of independent variables in the model.

Answer

The significance of the model.

Question 29

Principal Component Analysis (PCA) is primarily used for:

Accepted Answer

Reducing the dimensionality of a dataset by identifying its most significant features.

Answer

Predicting continuous dependent variables using categorical independent variables.

Answer

Clustering data points into distinct groups.

Question 30

Measures of central tendency summarize the typical value of a dataset. Which of the following is NOT a measure of central tendency?

Accepted Answer

Variance

Answer

Mode

Answer

Mean

Answer

Median

Question 31

In a standard six-sided die, each side has an equal probability of landing facing up. What is the probability of rolling a 6?

Accepted Answer

1/6

Answer

1/3

Answer

1/5

Answer

1/4

Question 32

Sampling methods aim to select a representative subset of a population for study. Which of the following sampling methods is most likely to produce a sample that is not representative of the population?

Accepted Answer

Convenience sampling

Answer

Cluster sampling

Answer

Stratified sampling

Answer

Simple random sampling

Question 33

In hypothesis testing, the null hypothesis represents a claim of no effect or difference. Which of the following statements is the null hypothesis in a statistical test?

Accepted Answer

There is no difference between the groups being compared.

Answer

The mean of the first group is greater than the mean of the second group.

Answer

There is a difference between the groups being compared.

Question 34

Statistical tests allow researchers to assess the significance of observed differences. Which of the following statistical tests is used to compare the means of two independent groups?

Accepted Answer

Independent samples t-test

Answer

Chi-square test

Answer

Paired samples t-test

Answer

One-way ANOVA

Question 35

Data visualization techniques help researchers explore and present data. Which of the following is a type of data visualization that displays the relationship between two variables?

Accepted Answer

Scatterplot

Answer

Histogram

Answer

Bar chart

Question 36

Machine learning involves training models to make predictions or uncover patterns from data. What is the key difference between supervised and unsupervised learning?

Accepted Answer

In supervised learning, models are trained on labeled data, while in unsupervised learning, models are trained on unlabeled data.

Answer

Supervised learning is used for classification tasks, while unsupervised learning is used for regression tasks.

Question 37

Working with Big Data presents unique challenges. Which of the following is a primary challenge associated with Big Data?

Accepted Answer

Data storage and management

Answer

Data visualization

Answer

Data analysis

Answer

Data collection

Question 38

In the field of Big Data analytics, data scientists play a crucial role. What is the primary responsibility of data scientists?

Accepted Answer

Extracting insights from data and building predictive models

Answer

Visualizing data

Answer

Collecting and cleaning data

Question 39

Which measure of central tendency is most sensitive to extreme values, making it less reliable when outliers are present?

Accepted Answer

Mean

Answer

Mode

Answer

Median

Answer

Range

Question 40

To determine if there is a statistically significant difference between the means of two groups, which statistical test is most appropriate?

Accepted Answer

t-test

Answer

Regression

Answer

Correlation

Answer

ANOVA

Question 41

When predicting a continuous outcome based on a single predictor variable, which regression model is most commonly used?

Accepted Answer

Linear regression

Answer

Poisson regression

Answer

Logistic regression

Answer

Decision tree

Question 42

To visually identify trends and patterns in data collected over time, which data visualization technique is most effective?

Accepted Answer

Line chart

Answer

Scatter plot

Answer

Bar chart

Answer

Pie chart

Question 43

In statistical modeling, what is the primary purpose of dividing a dataset into a training set and a test set?

Accepted Answer

Evaluate the performance of the statistical model

Answer

Explore the data

Answer

Train the statistical model

Answer

Represent the entire population

Question 44

In hypothesis testing, the null hypothesis typically represents which assumption?

Accepted Answer

There is no significant difference or effect

Answer

The alternative hypothesis is true

Answer

The data support the research question

Question 45

Which of the following algorithms is categorized as an unsupervised learning technique?

Accepted Answer

K-means clustering

Answer

Decision tree

Answer

Logistic regression

Answer

Linear discriminant analysis

Question 46

Which statistical measure is most appropriate for describing the center of a dataset that contains extreme outliers?

Accepted Answer

Median

Answer

Standard Deviation

Answer

Mean

Answer

Mode

Question 47

A data scientist is analyzing customer purchase data and observes a strong positive correlation between the number of items purchased and the total amount spent. What can be concluded from this correlation?

Accepted Answer

There is a relationship between the number of items purchased and the total amount spent, but it does not necessarily imply causation.

Answer

Purchasing more items directly causes customers to spend more money.

Question 48

Which of the following is a common statistical technique used to identify and visualize relationships between variables?

Accepted Answer

Regression analysis

Answer

Data cleaning

Answer

Hypothesis testing

Answer

Descriptive statistics

Question 49

A company wants to understand the effectiveness of a new marketing campaign. They collect data on website visits, email opens, and sales before and after the campaign launch. Which statistical test would be most appropriate to compare the data before and after the campaign?

Accepted Answer

Paired t-test

Answer

Linear regression

Answer

Chi-square test

Answer

ANOVA

Question 50

A data scientist is analyzing user behavior on a social media platform. Which data visualization technique would be most effective for showing the distribution of user ages?

Accepted Answer

Histogram

Answer

Pie chart

Answer

Scatter plot

Answer

Bar chart

Question 51

What is the purpose of data normalization in statistical analysis?

Accepted Answer

To ensure that variables are measured on the same scale, making comparisons meaningful.

Answer

To remove outliers from the data.

Answer

To reduce the number of variables in the dataset.

Question 52

A company is trying to predict customer churn using historical data. Which statistical model would be most appropriate for this task?

Accepted Answer

Logistic Regression

Answer

Decision Tree

Answer

K-Means Clustering

Answer

Linear Regression

Question 53

What is the primary difference between descriptive and inferential statistics?

Accepted Answer

Descriptive statistics summarizes existing data, while inferential statistics uses data to make predictions about a larger population.

Answer

Descriptive statistics uses quantitative data, while inferential statistics uses qualitative data.

Question 54

A company is conducting a survey to understand customer satisfaction. They want to ensure that the sample accurately reflects the demographics of their customer base. Which sampling technique should they use?

Accepted Answer

Stratified Sampling

Answer

Snowball Sampling

Answer

Convenience Sampling

Answer

Simple Random Sampling

Question 55

A data scientist is analyzing data from a sensor network that monitors environmental conditions. They notice a significant increase in the number of outlier readings. What should they do?

Accepted Answer

Investigate the potential causes of the outliers and determine if they are valid or due to errors.

Answer

Replace the outliers with the average value of the data.

Answer

Remove the outliers from the dataset without further investigation.