Conscientiousness Is a Tendency to Show Self-Discipline, Act Dutifully, and Aim

Multiple Choice

Conscientiousness is a tendency to show self-discipline, act dutifully, and aim for achievement. The trait shows a preference for planned rather than spontaneous behavior. A random sample of 650 students is asked to fill out the Hogan Personality Inventory (HPI) to measure their level of conscientiousness. The 300 undergraduate students scored an average of 145 with a standard deviation of 16. The 350 graduate students had a mean score of 153 with a standard deviation of 21. What is the standard error for the difference between the two sample means?

A) 18.5
B) 2.11
C) 1.45
D) 2.05