For any distribution, what is the z-score corresponding to the mean?

Elizabeth is 4 years old, and she likes to help her mother when it is time for supper. However, her mother is often quick tempered at the end of the day, scolding Elizabeth when she tries to help

Her mother finds she can get things done more quickly if Elizabeth stays out of the way. Based on Erikson's theory, Elizabeth may develop: a) a general sense of mistrust. b) feelings of guilt. c) feelings of inferiority. d) feelings of despair.

To reconcile Spearman's and Thurstone's views, current theorists and test designers assume that

A) a unique s factor is reflected in each of Thurstone's primary factors. B) at the highest level, g is presumed to be present to some degree in all separate factors. C) at the highest level, s is presumed to be present to some degree in all separate factors. D) g reflects fluid intelligence and s reflects crystallized intelligence.