Managers perceived employee stock ownership as having a significant positive effect on product quality. As part of that same study, managers were also asked to rate the effect of employee stock ownership on unit labor cost.24 This effect, on a scale from 2 (large negative effect) to 2 (large positive effect), was 0.12 with a standard error of 0.11, based on a sample of 343 managers. 

a. Find the 95% confidence interval and state carefully what this represents. Keep in mind that these are opinions of randomly selected managers. 

b. Is there a significant relationship between employee stock ownership and the unit cost of labor as perceived by managers? Why or why not? 

c. Identify the null and research hypotheses. 

d. Which hypothesis has been accepted? Is this a weak or a strong conclusion? 

e. Has the accepted hypothesis been absolutely proven? If not, what type of error may have been made?