28 + vector b   = -12
vector b  = -40  
vector b has magnitude 40 units in the negative y direction.
 
        
             
        
        
        
Answer:
42.1% of variation in the response is explained by the regression line
Step-by-step explanation:
Correlation coefficient is a measure which tells us that how strongly are two variables under study are linearly related to each other i.e correlation coefficient gives the strength of linear association between the variables. 
If the magnitude of correlation coefficient is closer to 1, it indicates a strong linear relationship. If the magnitude of correlation coefficient is closer to 0, it indicates a weak linear relationship.
There is another variable known as "Coefficient of Determination", which is equal to square of Correlation Coefficient. Coefficient of Determination tells us that what percentage of variation in the response of the study can be explained by the regression line.
This means, for this question we need to calculate the Coefficient of Determination.
Correlation coefficient = r = 0.649
Coefficient of Determination = R = r² = (0.649)²= 0.421 = 42.1 %
This means that 42.1% of variation in the response is explained by the regression line.
 
        
             
        
        
        
Dana can type 90 words per minute.
Since, 1 minute =  hours
 hours
Therefore, number of words she can type = 
                                                                       = 90×60
                                                                       = 5400 words per hour
If she types  words in 'x' hours.
 words in 'x' hours.
Number of words Dana types with the given speed in 'x' hours = Speed of typing × Time 
= 
Therefore, 


 hours
 hours
Therefore, Dana types  words in 48.15 hours.
 words in 48.15 hours.
Learn more,
brainly.com/question/621754