"An industrial/organizational psychologist has been consulting with a company that runs weekend job-seeking workshops for the unemployed. She collected data on several issues related to these workshops and, after conducting statistical tests, obtained statistically significant findings. She needs to find a way to evaluate effect size so that she can make recommendations to the company:
One of the psychologist's findings is that 18 months after the workshop, a sample of 81 job seekers who received training on setting career goals worked more than 30 hours per week an average of 8. months in the last year; with a standard deviation of 4.1. The typical job seeker works 7.4 months_
The psychologist finds that the estimated Cohen's d is
(three decimals)"