- Assume that a population of thousands of people whose responses were used to develop an

anxiety test had scores that were normally distributed with *M *= 30 and *s* = 10. What

proportion of people in this population would have anxiety scores within each of the following

ranges of scores?

- Below 20.
- Above 30.
- Between 10 and 50.

- What is
*SE*_{M}? What does the value of SE_{M} tell you about the typical magnitude of sampling

* *

* error? *

*As s increases, how does the size of SE*_{M} change (assuming that N stays the same)?

- As
*N increases, how does the size of SE*_{M} change (assuming that s stays the same)?

- Under what circumstances should a
*t *distribution be used rather than the normal distribution

to look up areas or probabilities associated with distances from the mean?