Data Analysis Fundamentals Flashcards
7 cards from real DAC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Data Analysis Fundamentals flashcards as text
Which chart type best displays the proportion of a whole across a few categories?
Answer: Pie chart
A pie chart shows each category's share of a total.
A correlation coefficient of -0.9 between two variables indicates what?
Answer: Strong negative relationship
A value near -1 signals a strong inverse (negative) linear relationship.
What is the purpose of data normalization before analysis?
Answer: To scale features to a comparable range
Normalization rescales values so variables with different units can be compared fairly.
Which sampling method gives every member of a population an equal chance of selection?
Answer: Simple random sampling
Simple random sampling gives each unit an equal, independent selection probability.
A histogram is most useful for showing what about a single numeric variable?
Answer: Its distribution
Histograms group values into bins to reveal the shape of a distribution.
In a dataset, 'gender' stored as Male/Female/Other is which kind of variable?
Answer: Categorical
Values that are labels with no inherent numeric order are categorical.
What does an outlier detected by the IQR method fall outside of?
Answer: 1.5 times the interquartile range from the quartiles
The IQR rule flags points beyond 1.5×IQR below Q1 or above Q3 as outliers.