The lapping process, which is used to grind certain silicon wafers to the proper thickness, is acceptable only if 'sigma', the population standard deviation of the thickness of dice cut from the wafers, is at most 0.50 mil. Use the 0.05 level of significance to test the null hypothesis 'sigma' = 0.50 against the alternative hypothesis 'sigma' > 0.50, if the thickness of 15 dice cut from such wafer have a standard deviation of 0.64 mil.
a) What is the equation of the regression line for the pairs (X,Y) shown below? Assume Y on X regression line.
b) What Y is predicted when X=72?
Regression analysis, Testing of Standard deviation.