Question 1147075:  Given are five observations for two variables, x and y. 
xi 
1	2	3	4	5 
yi 
2	8	6	11	13 
(a) 
Develop a scatter diagram for these data.
 
A scatter diagram has 5 points plotted on it. The horizontal axis ranges from 0 to 6 and is labeled: x. The vertical axis ranges from 0 to 18 and is labeled: y. The points are plotted from left to right in increments of 1 starting in the upper left corner of the diagram. The first 2 points are between 11 to 13 on the vertical axis. The next 3 points are between 2 to 8 on the vertical axis. 
   
A scatter diagram has 5 points plotted on it. The horizontal axis ranges from 0 to 6 and is labeled: x. The vertical axis ranges from 0 to 18 and is labeled: y. The points are plotted from left to right in increments of 1 in an upward, diagonal direction starting in the lower left corner of the diagram. The points are between 2 to 13 on the vertical axis. 
  
A scatter diagram has 5 points plotted on it. The horizontal axis ranges from 0 to 6 and is labeled: x. The vertical axis ranges from 0 to 18 and is labeled: y. The points are plotted from left to right in increments of 1 in a downward, diagonal direction starting in the upper left corner of the diagram. The points are between 2 to 13 on the vertical axis. 
   
A scatter diagram has 5 points plotted on it. The horizontal axis ranges from 0 to 6 and is labeled: x. The vertical axis ranges from 0 to 18 and is labeled: y. The points are plotted from left to right in increments of 1 in an upward, diagonal direction starting in the lower left corner of the diagram. The points are between 1 to 12 on the vertical axis. 
  
Correct: Your answer is correct. 
(b) 
What does the scatter diagram developed in part (a) indicate about the relationship between the two variables? 
There appears to be a negative linear relationship between x and y. 
There appears to be a positive linear relationship between x and y.     
There appears to be no noticeable relationship between x and y. 
Correct: Your answer is correct. 
(c) 
Try to approximate the relationship between x and y by drawing a straight line through the data.
 
A scatter diagram has 5 points on it. The horizontal axis ranges from 0 to 6 and is labeled: x. The vertical axis ranges from 0 to 18 and is labeled: y. A straight line with negative slope is imposed onto the diagram to approximate the relationship between x and y implied by the points, with 2 points lying below the line. The points are plotted from left to right in increments of 1 starting in the upper left corner of the diagram. The first 2 points are between 11 to 13 on the vertical axis. The next 3 points are between 2 to 8 on the vertical axis. 
   
A scatter diagram has 5 points on it. The horizontal axis ranges from 0 to 6 and is labeled: x. The vertical axis ranges from 0 to 18 and is labeled: y. A straight line with positive slope is imposed onto the diagram to approximate the relationship between x and y implied by the points, with 2 points lying below the line. The points are plotted from left to right in increments of 1 in an upward, diagonal direction starting in the lower left corner of the diagram. The points are between 2 to 13 on the vertical axis. 
  
A scatter diagram has 5 points on it. The horizontal axis ranges from 0 to 6 and is labeled: x. The vertical axis ranges from 0 to 18 and is labeled: y. A straight line with positive slope is imposed onto the diagram to approximate the relationship between x and y implied by the points, with 2 points lying below the line. The points are plotted from left to right in increments of 1 in an upward, diagonal direction starting in the lower left corner of the diagram. The points are between 1 to 12 on the vertical axis. 
   
A scatter diagram has 5 points on it. The horizontal axis ranges from 0 to 6 and is labeled: x. The vertical axis ranges from 0 to 18 and is labeled: y. A straight line with negative slope is imposed onto the diagram to approximate the relationship between x and y implied by the points, with 2 points lying below the line. The points are plotted from left to right in increments of 1 in a downward, diagonal direction starting in the upper left corner of the diagram. The points are between 2 to 13 on the vertical axis. 
  
Correct: Your answer is correct. 
(d) 
Develop the estimated regression equation by computing the values of  
b0 
 and  
b1 
 using  
b1 =  
Σ(xi − x)(yi − y) 
Σ(xi − x)2 
 and  
b0 = y − b1x. 
ŷ =   
   
Incorrect: Your answer is incorrect. 
(e) 
Use the estimated regression equation to predict the value of y when  
x = 2. 
  
 
 Answer by ikleyn(52903)      (Show Source): 
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