F(a) = (z, - a)? (7) i=1 is minimal when a = . (As a consequence, the sample mean is also called the least squares estimator of the population mean.)

A study of IT companies has found the following data on the age of each company and its annual volume of sales:               Age (years)      Sales (000)             2                22             2.5             34             3                33             4                37             4.5             40             4.5             45             5                49             3                30             6                58             6.5             58     (a)   Determine the least squares regression that relates the age of company variable to the sales variable in the form y = a + bx.                                                                 (b)   Provide a practical interpretation of the coefficients a and b.   (c)   Determine the ‘goodness of fit’ (R2) of the estimated regression line.   d) Using the estimated regression line determined in (a), calculate what volume of sales would be predicted for a company that is 3.5 years of age.   (e)   If it was found that…

Are MRI count and IQ linearly​ related?   Because the correlation coefficient for females is negative/positiveand the absolute value of this correlation​ coefficient, enter your response here​#, is greater/not greater than enter your response here#​, the critical value for the female data​ set,no/a positive/a negativerelation exists between MRI count and IQ for females. Because the correlation coefficient for males is negative/positive and the absolute value of this correlation​ coefficient, enter your response here#​, is greater/not greater than the critical value for the male data​ set, enter your response here​#,no/a positive/a negative relation exists between MRI count and IQ for males. ​(Round to three decimal places as​ needed.)       Critical value table 3 0.997 4 0.950 5 0.878 6 0.811  7 0.754 8 0.707 9 0.666 10 0.632 11 0.602 12 0.576 13 0.553 14 0.532 15 0.514 16 0.497 17 0.482 18 0.468 19 0.456 20 0.444 21 0.433 22 0.423 23 0.413 24 0.404 25 0.396 26 0.388 27 0.381 28 0.374…

A recent Gallup survey of a random sample of Americans (18 and older) found that the average number of alcoholic drinks consumed per week (drinks) by males was 4.2 and by females was 1.4.[1] Suppose we use the underlying survey data to estimate a least-squares regression of the average number of drinks a person reports consuming per week (Drinks;) on a dummy variable equal to 1 if i is female and O otherwise (Female;). (Assume all respondents identify as either male or female.) The estimated regression line equation can be written as: Drinks = a +bFemale Alcohol Consumption by Gender Because Female is a dummy variable, the problem provides us with enough information to figure out the exact regression line equation. What is the numerical value of a?