The following table is a summary of x and y data. a. The following scatterplot i
ID: 3174997 • Letter: T
Question
The following table is a summary of x and y data. a. The following scatterplot is for this data set. Does the relationship appear linear? Also, do you expect beta_1 to be negative or positive? b. Using the data provided, create the table found on page 47 in the workbook. c. Obtain the least squares line. Continued d. Predict the value of the response when x is 5 and 9. Which of these predictions is meaningful? e. What is the residual for observation 1? f. What is the estimated standard error of the model (s)?Explanation / Answer
Step 1: Find XY and X2 as it was done in the table below.
Step 2: Find the sum of every column:
X=24 , Y=31 , XY=80 , X2=116
Step 3: Use the following equations to find a and b:
a=YX2XXY/nX2(X)2=31116248071162427.102
b=nXYXY/nX2(X)2=78024317116(24)20.78
Step 4: Substitute a and b in regression equation formula
y = a + bx= 7.102 0.78x
X Y XY XX 7 2 14 49 4 4 16 16 6 2 12 36 2 5 10 4 1 7 7 1 1 6 6 1 3 5 15 9