Statistical Analysis Flashcards
6 cards from real Data and Analytics practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Statistical Analysis flashcards as text
What is the Central Limit Theorem (CLT)?
Answer: The sampling distribution of the mean approaches normal as sample size increases
The CLT states that the sampling distribution of the sample mean approximates a normal distribution as sample size increases, regardless of population distribution.
What does R-squared (R²) measure in regression analysis?
Answer: The proportion of variance in the dependent variable explained by the model
R-squared measures the proportion of variance in the dependent variable that is explained by the independent variable(s) in the model.
What is the interquartile range (IQR)?
Answer: The difference between the 75th and 25th percentiles
The IQR is Q3 minus Q1, representing the spread of the middle 50% of data and used to identify outliers.
Which statistical test compares means across more than two independent groups?
Answer: ANOVA
ANOVA (Analysis of Variance) tests whether the means of three or more independent groups are significantly different.
What is a confidence interval?
Answer: A range of values likely to contain the true population parameter
A confidence interval provides a range of plausible values for a population parameter with a specified level of confidence (e.g., 95%).
What is multicollinearity in regression analysis?
Answer: High correlation among independent predictor variables
Multicollinearity occurs when two or more independent variables in a regression model are highly correlated, making it difficult to isolate individual effects.