The following data resulted from an experiment performed for the purpose of regression analysis. The input variable, x, was set at five different levels, and observations were made at each level.

a. Draw a scatter diagram.
b. Draw the regression line by eye.
c. Place a star, _, at each level approximately where the mean of the observed y values is located. Does your regression line look like the line of best fit for these five mean values?
d. Calculate the equation of the regression line.
e. Find the standard deviation of y about the regression line.
f. Construct a 95% confidence interval for the true value of b1.
g. Construct a 95% confidence interval for the mean value of y at x = 3.0 and at x = 3.5
h. Construct a 95% prediction interval for an individual value of y at x = 3.0 and at x = 3.5.

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