For each of the following situations, state whether the mean would be a statistic or a parameter. Explain your answer. 

a. According to Canadian census data, the median family income in British Columbia was $66,970, lower than the national average of $69,860. 

b. The stadiums of teams in the English Premier League had a mean capacity of 38,391 fans. 

c. The General Social Survey (GSS) includes a vocabulary test in which participants are asked to choose the appropriate synonym from a multiple-choice list of five words (e.g., beast with the choices afraid, words, large, animal, and separate). The mean vocabulary test score was 5.98. 

d. The National Survey of Student Engagement (NSSE) asks students at participating institutions how often they discuss ideas or readings with professors outside of class. Among the 19 national universities that made their data public, the mean percentage of students who responded “Very often” was 8%.