A rock band is trying to predict the number of CDs they will sell per week based on the number of hits they get on their web site which has a sample clip on it. They collect data from 13 previous weeks and entered it into a statistical computer package.
Based on the provided scatterplot, the correlation between number of web site hits and number of CDs sold will be _____.
1.positive
2.negative
3.nearly 0
4.none of the above
Q. 2In a random sample of eight college women, each was asked her height (to the nearest inch) and her weight (to the nearest five pounds). Part of the Minitab output obtained is shown below.
Regression Analysis: weight versus height
Predictor Coef SE Coef T P
Constant -182.81 66.55 -2.75 0.033
height 4.635 1.007 4.60 0.004
S = 9.86673 R-Sq = 77.9 R-Sq(adj) = 74.3
What is the correlation coefficient?
1.0.779
2.0.743
3.0.883
4.It can not be determined from the given output.
Q. 3In a random sample of eight college women, each was asked her height (to the nearest inch) and her weight (to the nearest five pounds). Part of the Minitab output obtained is shown below.
Regression Analysis: weight versus height
Predictor Coef SE Coef T P
Constant -182.81 66.55 -2.75 0.033
height 4.635 1.007 4.60 0.004
S = 9.86673 R-Sq = 77.9 R-Sq(adj) = 74.3
What is the regression equation?
1. = 4.635x 182.81
2. = 182.81x + 4.635
3. = 66.55x + 1.007
4. = 1.007x + 66.55
Q. 4The least squares criterion requires that _____.
1.the sum of squared differences between the actual y's and the average y's be minimized
2.the sum of the squared differences between the actual y's and the predicted y's be as small as possible
3.the sum of the squared differences between the actual y's and the predicted y's be as large as possible
4.the sum of the differences between the actual y's and the predicted y's be as small as possible
Q. 5The regression equation relating x, the number of hours one studied, to y, the exam grade is determined to be = 4.1x + 68.7. Predict the exam grade of someone who studied one and a half hours.
1.approximately 75
2.approximately 58
3.approximately 100
4.approximately 69
Q. 6The regression equation relating x, the number of hours one studied, to y, the exam grade is determined to be = 4.1x + 68.7. From this equation, one can conclude that
1.On average, each additional hour of studying will increase the exam grade by approximately four points.
2.On average, each additional hour of studying will increase the exam grade approximately 69 points.
3.If one studies four hours, the exam grade will be approximately a 69.
4.The effect of one additional hour of studying can not be determined unless it is known how long one studied.
Q. 7The correlation between the height and weight of 8 college-age women is obtained. The Minitab output is shown below.
Correlations: Height, Weight
Pearson correlation of Height and Weight = 0.865
P-Value = 0.006
What does the correlation coefficient indicate about the relationship?
1.There is a strong positive linear relationship between height and weight.
2.There is a weak positive linear relationship between height and weight.
3.There is a strong negative relationship between height and weight.
4.There is a strong positive nonlinear relationship between height and weight.
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