Stats Chapters 1 -3 Review

Front

What does a strong positive correlation indicate in a graph?

Back

A strong positive correlation indicates that as one variable increases, the other variable also increases significantly.

Front

What is a residual in statistics?

Back

A residual is the distance between the observed value and the predicted value (y - y-hat) in a regression analysis.

Front

Interpret the slope of the equation y-hat = 16.2x + 20 in the context of ice cream sales.

Back

For every increase of 1 degree, we predict an increase of 16.2 ice cream cones sold.

Front

What does the slope of a regression line represent?

Back

The slope represents the change in the dependent variable for each unit change in the independent variable.

Front

How do you calculate the mean from a Z-score?

Back

Mean = x - (Z-score * Standard Deviation). For Z-score = -1.4, Standard Deviation = 7, and x = 20, the mean is 29.8.

Front

What is the formula for calculating a Z-score?

Back

Z-score = (X - Mean) / Standard Deviation.

Front

What does a Z-score of -1.4 indicate?

Back

A Z-score of -1.4 indicates that the value is 1.4 standard deviations below the mean.

Front

What is the significance of the y-intercept in a linear regression equation?

Back

The y-intercept represents the predicted value of the dependent variable when the independent variable is zero.

Front

How do you interpret the slope in the context of growth and weight in a regression model?

Back

For every additional hour of growth, the logarithm of the culture's weight in grams is predicted to increase by 0.61.

Front

What is the difference between correlation and causation?

Back

Correlation indicates a relationship between two variables, while causation indicates that one variable directly affects the other.