A psychologist is interested in examining the anxiety level of all postal workers. In particular, she would like to find out if the mean anxiety level of all such workers is the same as the general population. She takes 80 postal workers and has then taken the Putman test of anxiety. From this, she calculates the mean score for these 80 postal workers to be . For this situation: What is the research objective? The objective of the study is to examine the anxiety level of 80 postal workers What is the population? 80 postal workers What is the parameter involved? mean anxiety level of all postal workers What is the sample? 80 postal workers What is the descriptive statistic? the mean score for 80 postal workers