6 - Normal Distribution Flashcards
(10 cards)
What does a negative regression coefficient imply about the relationship between variables?
It implies an inverse relationship: as the predictor increases, the response variable tends to decrease.
What does a low standard error of the regression line suggest about the model’s accuracy?
It suggests that the predicted values are close to the actual data points—i.e., the model fits well.
Why do we examine residual plots in regression analysis?
To check assumptions like linearity, homoscedasticity, and independence of errors.
The standard error of the estimate measures how much the observed values deviate from the regression line on average. True or False?
False
What does a t-test in the context of regression assess?
Whether a regression coefficient is significantly different from zero.
The intercept in a regression model always has a meaningful interpretation in the context of the data. True or False?
False. Sometimes the intercept represents a value outside the scope of the data, making it not meaningful.
The standard error of a regression coefficient helps determine if the coefficient is significantly different from zero. True or False?
True
A wide confidence interval for a coefficient suggests high precision in the estimate. True or False?
False. A wide interval suggests low precision and more uncertainty.
The t-statistic for a coefficient is calculated by dividing the coefficient estimate by its standard error. True or False?
True.
In hypothesis testing, a p-value of 0.04 means there’s a 4% chance the null hypothesis is true. True or False?
False. The p-value is the probability of observing the data (or more extreme) assuming the null hypothesis is true—not the probability the null is true.
