AP Statistics Test #6 Review

What happens to the shape of the t-distribution as the degrees of freedom increase?

• The middle of the distribution becomes shorter, while the tails get higher, approximating a more uniform model.

• The distribution becomes more and more similar to a normal distribution.

• Nothing. But the results of the hypothesis test become less accurate.

• The middle of the distribution becomes shorter, while the tails get taller, resulting in a bimodal model.

What are the two types of probability distributions?

• Discrete and Continuous

• Geometric and Binomial

• Normal and Chi-Square

• Skewed Left and Skewed Right

What is the difference between relative frequency and probability?

• Relative is the theoretical; Probability is the actual

• Relative is out of 100%; Probability depends on n, number of trials

• Probability is the theoretical; Relative is the actual

What types of data can be described by a frequency distribution?

• Categorical

• Quantitative

What is the difference between a chi-square test and a correlation?

• A chi-square test is where you can determine a cause-and-effect relationship; a correlation cannot

• Nothing.

• A correlation is used when you have two categorical variables; chi-square is when you have two quantitative variables.

• A correlation is used when you have two quantitative variables; chi-square is when you have two categorical variables.

What happens to the shape of the chi-square distribution as the degrees of freedom increase?

• Nothing.

• Eventually it will go from being right-skewed to normal.

• Eventually it will go from being right-skewed to left-skewed.

• It's peak will increase, becoming more right-skewed.

Given the regression analysis, what is the equation of the LSRL?

• y(hat)=38257x-0.163

• y(hat)=38257-0.163x

• y(hat)=2446-0.163x

• y(hat)=2446x-0.163

What is another name for the "coefficient of determination?"

• R-Squared Value

• R-Value

• Correlation Coefficient

• Slope

Interpret the coefficient of determination from the computer output seen here:

• As the price increases, the miles driven go up by about 66.4%

• As the miles driven increase, the price increases by about 66.4%.

• About 66.4% of the variability in miles driven is accounted for by the LSRL.

• About 66.4% of the variability in price is accounted for by the LSRL.

Researchers are testing a new diagnostic tool designed to identify a certain condition. The null hypothesis of the

significance test is that the diagnostic tool is NOT effective in detecting the condition. For the researchers, the more

consequential error would be that the diagnostic tool is not effective, but the significance test indicated that it is

effective. Which of the following should the researchers do to avoid the more consequential error?

• Increase the significance level to increase the probability of Type I error

• Increase the significance level to decrease the probability of Type I error.

• Decrease the significance level to increase the probability of Type I error

• Decrease the significance level to decrease the probability of Type I error.