Across
- 2. models random events by using random numbers to specify event outcomes with relative frequencies that correspond to the true real-world relative frequencies we are trying to model
- 6. the differences between data values and the corresponding values predicted by the regression model; ____ = observed value - predicted value
- 7. tells how many standard deviations a value is from the mean; have a mean of zero and a standard deviation of one
- 9. when omitting a point from the data results in a very different regression model, the point is an ____
- 10. The coefficient of is the square of the correlation between y and x; gives the fraction of the variability of y accounted for by the least squares linear regression on x; an overall measure of how successful the regression is in linearly relating y to x
- 12. this gives a starting value in y-units; it's the y-hat-value when x is 0
- 13. a scatterplot shows an association that is this if there is little scatter around the underlying relationship
- 14. value found by substituting the x-value in the regression equation; they're the values on the fitted line
- 16. value calculated from data to summarize aspects of the data
- 17. values of this variable record the results of each trial with respect to what we were interested in
- 18. useful family of models for unimodal, symmetric distributions
- 20. gives a value in "y-units per x-unit"; changes of one unit in x are associated with changes of b1 units in predicted values of y
Down
- 1. an equation or formula that simplifies and represents reality
- 2. shows the relationship between two quantitative variables measured on the same cases
- 3. a variable other than x and y that simultaneously affects both variables, accounting for the correlation between the two
- 4. a numerical measure of the direction and strength of a linear association
- 5. the ____ we care about most in a scatterplot is linear
- 8. done to eliminate units; values can be compared and combined even if the original variables had different units and magnitudes
- 11. although linear models provide an easy way to predict values of y for a given value of x, it is unsafe to predict for values of x far from the ones used to find the linear model equation; predictions should not be trusted
- 15. a positive ____ or association means that, in general, as one variable increases, so does the other; when increases in one variable generally correspond to decreases in the other, the association is negative
- 19. model an equation of the form y-hat = a + bx
- 21. squares this method specifies the unique line that minimizes the variance of the residuals or, equivalently, the sum of the squared residuals