BESC 3010 Ch. 11

Which of the following is an impossible value for .00 1.00 -.01 .99

-.01

If X and Y in a regression equation are both expressed as z scores -z Xandz Y- and the correlation between the two variables is r = .3, then what is the predicted value ofz Y when z X= - 1.2? -1.23 -0.36 3.6 Cannot be determined without additional information

-0.36

What is the predicted value of Y when X = 20 using this regression equation? Y = 12 - 0.8*X -4 224 11.2 -16

-4

If X and Y in a regression equation are both expressed as z scores - z x and z y - and the correlation between the two variables is r = -.2, then what is the predicted value of z y when z x = - 0.5? 1.0 0.1 -0.5 -0.1

0.1

Which of the following is an impossible value for .16 .36 .00 1.10

1.10

What is the predicted value of Y when X = 120 using this regression equation? Y = -350 + 5*X 250 950 475 Cannot be calculated without additional information

250

If the mean of X is 42, the mean of Y = 72, and r X Y= 0, then what is the predicted value of Y when X = 30? x Cannot be predicted without additional information 72 42 x 0

72

What is the predicted value of Y when X = 10 using this regression equation? Y = 30 - 1.2*X 18 Cannot be calculated without additional information 28.8 10

= 18

Which of the following is true about regression towards the mean? Predicted Y values will not always be perfect unless r = ± 1 Predicted Y values tend to be closer to the mean of Y than the observed values of X are to the mean of X All of the answers are correct Predicted Y values will have less variation than actual observed values of Y

All of the answers are correct

Which of the following is true about regression towards the mean? Predicted Y values will not be perfectly accurate unless r = ± 1 All of the answers are correct Predicted Y values tend to be closer to the mean of Y than the observed values of X are to the mean of X Predicted Y values will have less variation than observed values of Y

All of the answers are correct

If the dots on a scatterplot are spread out randomly, the researcher would report the correlation as: Weak and negative Weak and positive Close to zero Strong and positive

Close to zero

What is the minimum level of measurement to calculate Pearson's r correlation coefficient? Ratio Ordinal Nominal Interval

Interval

What is the minimum level of measurement to calculate a Pearson's r correlation coefficient? Ratio Nominal Ordinal Interval

Interval

If r = .65, then the members in a sample who have _____ values on the independent variable have _____ values on the dependent variable. Lower, higher Higher, lower No relationship Lower, lower

Lower, lower

Which statistic is defined as the proportion of variance accounted in the dependent variable by the independent variable? Range Chi-squared R-squared Mode

R-squared

Which of the following illustrates a negative correlation? The more often a person visits the dentist, the fewer cavities they have. As a person writes less, the quality of their writing decreases. The less often a person gets sick, the less sick days they would need to take off work. The more often a person exercises, the more muscle mass they will accumulate.

The more often a person visits the dentist, the fewer cavities they have.

If a regression equation is calculated for a sample of data and then a person who is an outlier on both X and Y is added, what would likely happen to the regression equation? The new score would likely change the intercept but not the slope The new score would have no predictable effect on either the intercept or the slope The new score would likely change the slope but not the intercept The new score would likely change both the intercept and the slope

The new score would likely change both the intercept and the slope

If a person has a middling score on X but a very high score on Y, what would their effect on the regression equation be? They would not change the intercept but they would raise the slope They would raise the intercept but not change the slope They would no predictable effect on either the intercept or the slope They would raise the intercept and raise the slope

They would raise the intercept but not change the slope

If the dots on a scatterplot generally extend from the bottom left to the upper right of the diagram but are very widely spread out, the researcher would report the correlation as: Weak and positive Strong and negative Strong and positive Close to zero

Weak and positive

When people who score low on one variable tend to score low on another variable, then those two variables... are negatively correlated. have a significant interaction. are positively correlated. have a significant main effect.

are positively correlated.

Correlations (using the Pearson product moment correlation coefficient) may be uninterpretable and inappropriate if the data... have a nonlinear relationship. come from a sample with n < 20. are interval level. are inversely related.

have a nonlinear relationship.

If r = -.4, then the people who have _____ values on the predictor variable generally have _____ values on the outcome variable. lower, higher lower, lower moderate, unpredictable higher, higher

lower, higher

If the dots on a scatterplot generally extend from the top left to the bottom right of the diagram but are very widely spread out, the researcher would report the correlation as... negative but weak. positive and strong. negative and strong. positive but weak.

negative but weak.

The relationship in this scatterplot is... direct. nonlinear linear open-ended

nonlinear

What is the non-directional null hypothesis for correlation? r < 1 (or rho < 1) r = 0 (or rho = 0) r > 0 (or rho > 0) r = 1 (or rho = 1)

r = 0 (or rho = 0)

When a regression equation doesn't predict a person's score perfectly, then the difference between their predicted score and their actual score is the... measurement error. error ratio. residual. deviation.

residual

The difference between a predicted Y score and an actual observed Y score is known as the... residual. error ratio. All of the answers are correct imperfection coefficient.

residual.

The vertical distance between a person's predicted score on Y and their actual score on Y is called _____ and it signifies _____. the residual; error in prediction the standard error; error in measurement the deviation; the average of how far each score is from the regression line displacement; regression to the mean

the residual; error in prediction

The vertical distance between a person's predicted score on Y and their actual score on Y is called _____ and it signifies _____. the standard error; error in measurement the residual; error in prediction displacement; regression to the mean the deviation; the average of how far each score is from the regression line

the residual; error in prediction

If X and Y in a regression equation are both expressed as z scores - z Y> 1 z Y>z X z X=z Y z X>

z Y>z X