Two variables have a positive linear correlation. Does the dependent variable increase or decrease as the independent variable increases?

Two variables have a positive linear correlation. Does the dependent variable increase or decrease as the independent variable increases?

 

  Cannot determine from information given

 

  Dependent variable would remain the same

 

  Dependent variable increases

 

  Dependent variable decreases

 

 Question 2What does the variable r represent?

 

  The critical value for the correlation coefficient

 

  The sample correlation coefficient

 

  The coefficient of determination

 

  The population correlation coefficient

 

 Question 3A golfer wants to determine if the type of driver she uses each year can be used to predict the amount of improvement in her game. Which variable would be the response variable?

 

  The improvement in her game

 

  The type of driver

 

  The rating of the golfer

 

  The number of holes she plays

 

 Question 4What would be the notation for an estimate of y for a specific value of x?

 

  yi

 

  y?

 

  ?

 

  b

 

 Question 5Which of the following graphs displays the regression equation ?=-0.91x + 11.97

 

 Scatter plot generally from upper left to lower right where y-intercept is estimated to be around 12

 

  Scatter plot generally from upper left to lower right where y-intercept is estimated to be around 7

 

  Scatter plot generally from lower left to upper right where y-intercept is estimated to be around 30

 

  Scatter plot generally from lower left to upper right where y-intercept is estimated to be around 6

 

 Question 6Find the regression equation for the following data set

 

 

 

x              142         167         143         189         175         174         134         155

 

y              20          80          72          69          44          59          51          63

 

  ? = 0.33x + 3.70

 

  cannot be determined

 

  ? = -0.33x + 3.70

 

  ? = 0.33x – 3.70

 

 Question 7A data set whose original x values ranged from 41 through 78 was used to generate a regression equation of ?=5.3x – 21.9. Use the regression equation to predict the value of y when x=56.

 

  Meaningless result

 

  1121.1

 

  274.9

 

  318.7

 

 Question 8A data set whose original x values ranged from 120 through 351 was used to generate a regression equation of ?=0.06x + 14.2. Use the regression equation to predict the value of y when x=110.

 

  21.34

 

  20.80

 

  Meaningless result

 

  -7.6

 

 Question 9A data set whose original x values ranged from 137 through 150 was used to generate a regression equation of ?=-4.5x + 51. Use the regression equation to predict the value of y when x=141.

 

  -574.5

 

  -685.5

 

  -583.5

 

  Meaningless result

 

 Question 10If the linear correlation coefficient is -0.368, what is the value of the coefficient of determination?

 

  0.736

 

  -0.135

 

  0.135

 

  0.184

 

 Question 11If the coefficient of determination is 0.497, what percentage of the variation in the data about the regression line is explained?

 

  49.7%

 

  50.3%

 

  24.7%

 

  50.0%

 

 Question 12If the coefficient of determination is 0.394, what percentage of the variation in the data about the regression line is unexplained?

 

  66.0%

 

  60.6%

 

  39.4%

 

  15.5%

 

 Question 13If the independent variables explained more than 50% of the variation in the dependent variables, which of the following would be true?

 

  There are two dependent variables

 

  The coefficient of determination is below 0.5

 

  The coefficient of determination is above 0.5

 

  There are two independent variables

 

 Question 14The equation used to predict how tall a dog will be as an adult is ?=4.5 + 0.7×1 + 0.55×2, where x1 is the height of the mother and x2 is the height of the father. Use this equation to predict the height of a puppy whose mother is 42.8 inches tall and whose father is 47.1 inches tall.

 

  61.01 inches

 

  60.37 inches

 

  44.95 inches

 

  55.87 inches

 

 Question 15The equation used to predict how long a cold will last is ?=-1.8 + 0.09×1 + 3.2×2 – 1.9×3, where x1

 

is person’s temperature on the first day, x2 is number of people seen each day, and x3 is the amount of sleep the person gets. Use this equation to predict how long a cold will last with a temperature of 100.8 degrees, an average of 3 people seen each day, and 6 hours of sleep.

 

  5.8 days

 

  7.3 days

 

  5.5 days

 

  8.7 days