Data Science Fundamentals Worksheet

What is the primary goal of data science?

• To collect as much data as possible

• To use data to gain insights and make decisions

• To replace human judgment entirely

• To create complex algorithms without application

Which of the following is an example of unstructured data?

• A CSV file of customer purchases

• A SQL database table

• A tweet containing text and emojis

• An Excel spreadsheet with sales figures

What does the "Venn Diagram of Data Science" include?

• Hacking skills, math/statistics, and domain expertise

• Coding, visualization, and cloud computing

• Data mining, AI, and robotics

• SQL, Python, and R

Which type of data is "zip code" classified as?

• Quantitative continuous

• Quantitative discrete

• Qualitative nominal

• Qualitative ordinal

What is the key assumption of the Central Limit Theorem?

• Data must be normally distributed

• Sample means will approximate normality as sample size increases

• Population variance must be known

• Samples must be biased

In hypothesis testing, what does a p-value < 0.05 typically indicate?

• Accept the null hypothesis

• Reject the null hypothesis

Which metric measures "how often a classifier is correct when it predicts positive"?

• Recall

• F1-score

• Precision

• Accuracy

What does Occam’s Razor suggest in modeling?

• Use the most complex model available

• The simplest explanation is usually best

• Always prioritize high accuracy over interpretability

• Add more features to improve performance

Which distance metric is calculated as √(Σ(x_i - y_i)²)?

• Manhattan distance

• Euclidean distance

• Cosine similarity

• Hamming distance

What is the purpose of z-score normalization?

• To convert categorical data to numerical

• To scale data to have mean=0 and standard deviation=1

• To remove outliers permanently

• To reduce dimensionality